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1/* vi: set sw=4 ts=4: */
2/*
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
7 *
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
10 *
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
12 *
13 * Credits:
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
23 * rewrites.
24 *
25 * Other credits:
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
30 *
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
41 *
42 * TODOs:
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
45 * tilde expansion
46 * aliases
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
52 *
53 * Bash compat TODO:
54 * redirection of stdout+stderr: &> and >&
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
58 * =~: regex operator
59 * let EXPR [EXPR...]
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
63 * ((EXPR))
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
67 *
68 * Won't do:
69 * In bash, export builtin is special, its arguments are assignments
70 * and therefore expansion of them should be "one-word" expansion:
71 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
72 * compare with:
73 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
74 * ls: cannot access i=a: No such file or directory
75 * ls: cannot access b: No such file or directory
76 * Note1: same applies to local builtin.
77 * Note2: bash 3.2.33(1) does this only if export word itself
78 * is not quoted:
79 * $ export i=`echo 'aaa bbb'`; echo "$i"
80 * aaa bbb
81 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
82 * aaa
83 */
84#if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
85 || defined(__APPLE__) \
86 )
87# include <malloc.h> /* for malloc_trim */
88#endif
89#include <glob.h>
90/* #include <dmalloc.h> */
91#if ENABLE_HUSH_CASE
92# include <fnmatch.h>
93#endif
94
95#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
96#include "unicode.h"
97#include "shell_common.h"
98#include "math.h"
99#include "match.h"
100#if ENABLE_HUSH_RANDOM_SUPPORT
101# include "random.h"
102#else
103# define CLEAR_RANDOM_T(rnd) ((void)0)
104#endif
105#ifndef PIPE_BUF
106# define PIPE_BUF 4096 /* amount of buffering in a pipe */
107#endif
108
109//config:config HUSH
110//config: bool "hush"
111//config: default y
112//config: help
113//config: hush is a small shell (25k). It handles the normal flow control
114//config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
115//config: case/esac. Redirections, here documents, $((arithmetic))
116//config: and functions are supported.
117//config:
118//config: It will compile and work on no-mmu systems.
119//config:
120//config: It does not handle select, aliases, tilde expansion,
121//config: &>file and >&file redirection of stdout+stderr.
122//config:
123//config:config HUSH_BASH_COMPAT
124//config: bool "bash-compatible extensions"
125//config: default y
126//config: depends on HUSH
127//config: help
128//config: Enable bash-compatible extensions.
129//config:
130//config:config HUSH_BRACE_EXPANSION
131//config: bool "Brace expansion"
132//config: default y
133//config: depends on HUSH_BASH_COMPAT
134//config: help
135//config: Enable {abc,def} extension.
136//config:
137//config:config HUSH_HELP
138//config: bool "help builtin"
139//config: default y
140//config: depends on HUSH
141//config: help
142//config: Enable help builtin in hush. Code size + ~1 kbyte.
143//config:
144//config:config HUSH_INTERACTIVE
145//config: bool "Interactive mode"
146//config: default y
147//config: depends on HUSH
148//config: help
149//config: Enable interactive mode (prompt and command editing).
150//config: Without this, hush simply reads and executes commands
151//config: from stdin just like a shell script from a file.
152//config: No prompt, no PS1/PS2 magic shell variables.
153//config:
154//config:config HUSH_SAVEHISTORY
155//config: bool "Save command history to .hush_history"
156//config: default y
157//config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
158//config: help
159//config: Enable history saving in hush.
160//config:
161//config:config HUSH_JOB
162//config: bool "Job control"
163//config: default y
164//config: depends on HUSH_INTERACTIVE
165//config: help
166//config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
167//config: command (not entire shell), fg/bg builtins work. Without this option,
168//config: "cmd &" still works by simply spawning a process and immediately
169//config: prompting for next command (or executing next command in a script),
170//config: but no separate process group is formed.
171//config:
172//config:config HUSH_TICK
173//config: bool "Process substitution"
174//config: default y
175//config: depends on HUSH
176//config: help
177//config: Enable process substitution `command` and $(command) in hush.
178//config:
179//config:config HUSH_IF
180//config: bool "Support if/then/elif/else/fi"
181//config: default y
182//config: depends on HUSH
183//config: help
184//config: Enable if/then/elif/else/fi in hush.
185//config:
186//config:config HUSH_LOOPS
187//config: bool "Support for, while and until loops"
188//config: default y
189//config: depends on HUSH
190//config: help
191//config: Enable for, while and until loops in hush.
192//config:
193//config:config HUSH_CASE
194//config: bool "Support case ... esac statement"
195//config: default y
196//config: depends on HUSH
197//config: help
198//config: Enable case ... esac statement in hush. +400 bytes.
199//config:
200//config:config HUSH_FUNCTIONS
201//config: bool "Support funcname() { commands; } syntax"
202//config: default y
203//config: depends on HUSH
204//config: help
205//config: Enable support for shell functions in hush. +800 bytes.
206//config:
207//config:config HUSH_LOCAL
208//config: bool "Support local builtin"
209//config: default y
210//config: depends on HUSH_FUNCTIONS
211//config: help
212//config: Enable support for local variables in functions.
213//config:
214//config:config HUSH_RANDOM_SUPPORT
215//config: bool "Pseudorandom generator and $RANDOM variable"
216//config: default y
217//config: depends on HUSH
218//config: help
219//config: Enable pseudorandom generator and dynamic variable "$RANDOM".
220//config: Each read of "$RANDOM" will generate a new pseudorandom value.
221//config:
222//config:config HUSH_EXPORT_N
223//config: bool "Support 'export -n' option"
224//config: default y
225//config: depends on HUSH
226//config: help
227//config: export -n unexports variables. It is a bash extension.
228//config:
229//config:config HUSH_MODE_X
230//config: bool "Support 'hush -x' option and 'set -x' command"
231//config: default y
232//config: depends on HUSH
233//config: help
234//config: This instructs hush to print commands before execution.
235//config: Adds ~300 bytes.
236//config:
237//config:config MSH
238//config: bool "msh (deprecated: aliased to hush)"
239//config: default n
240//config: select HUSH
241//config: help
242//config: msh is deprecated and will be removed, please migrate to hush.
243//config:
244
245//applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
246//applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
247//applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
248//applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
249
250//kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
251//kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
252
253/* -i (interactive) and -s (read stdin) are also accepted,
254 * but currently do nothing, therefore aren't shown in help.
255 * NOMMU-specific options are not meant to be used by users,
256 * therefore we don't show them either.
257 */
258//usage:#define hush_trivial_usage
259//usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
260//usage:#define hush_full_usage "\n\n"
261//usage: "Unix shell interpreter"
262
263//usage:#define msh_trivial_usage hush_trivial_usage
264//usage:#define msh_full_usage hush_full_usage
265
266//usage:#if ENABLE_FEATURE_SH_IS_HUSH
267//usage:# define sh_trivial_usage hush_trivial_usage
268//usage:# define sh_full_usage hush_full_usage
269//usage:#endif
270//usage:#if ENABLE_FEATURE_BASH_IS_HUSH
271//usage:# define bash_trivial_usage hush_trivial_usage
272//usage:# define bash_full_usage hush_full_usage
273//usage:#endif
274
275
276/* Build knobs */
277#define LEAK_HUNTING 0
278#define BUILD_AS_NOMMU 0
279/* Enable/disable sanity checks. Ok to enable in production,
280 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
281 * Keeping 1 for now even in released versions.
282 */
283#define HUSH_DEBUG 1
284/* Slightly bigger (+200 bytes), but faster hush.
285 * So far it only enables a trick with counting SIGCHLDs and forks,
286 * which allows us to do fewer waitpid's.
287 * (we can detect a case where neither forks were done nor SIGCHLDs happened
288 * and therefore waitpid will return the same result as last time)
289 */
290#define ENABLE_HUSH_FAST 0
291/* TODO: implement simplified code for users which do not need ${var%...} ops
292 * So far ${var%...} ops are always enabled:
293 */
294#define ENABLE_HUSH_DOLLAR_OPS 1
295
296
297#if BUILD_AS_NOMMU
298# undef BB_MMU
299# undef USE_FOR_NOMMU
300# undef USE_FOR_MMU
301# define BB_MMU 0
302# define USE_FOR_NOMMU(...) __VA_ARGS__
303# define USE_FOR_MMU(...)
304#endif
305
306#include "NUM_APPLETS.h"
307#if NUM_APPLETS == 1
308/* STANDALONE does not make sense, and won't compile */
309# undef CONFIG_FEATURE_SH_STANDALONE
310# undef ENABLE_FEATURE_SH_STANDALONE
311# undef IF_FEATURE_SH_STANDALONE
312# undef IF_NOT_FEATURE_SH_STANDALONE
313# define ENABLE_FEATURE_SH_STANDALONE 0
314# define IF_FEATURE_SH_STANDALONE(...)
315# define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
316#endif
317
318#if !ENABLE_HUSH_INTERACTIVE
319# undef ENABLE_FEATURE_EDITING
320# define ENABLE_FEATURE_EDITING 0
321# undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
322# define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
323# undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
324# define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
325#endif
326
327/* Do we support ANY keywords? */
328#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
329# define HAS_KEYWORDS 1
330# define IF_HAS_KEYWORDS(...) __VA_ARGS__
331# define IF_HAS_NO_KEYWORDS(...)
332#else
333# define HAS_KEYWORDS 0
334# define IF_HAS_KEYWORDS(...)
335# define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
336#endif
337
338/* If you comment out one of these below, it will be #defined later
339 * to perform debug printfs to stderr: */
340#define debug_printf(...) do {} while (0)
341/* Finer-grained debug switches */
342#define debug_printf_parse(...) do {} while (0)
343#define debug_print_tree(a, b) do {} while (0)
344#define debug_printf_exec(...) do {} while (0)
345#define debug_printf_env(...) do {} while (0)
346#define debug_printf_jobs(...) do {} while (0)
347#define debug_printf_expand(...) do {} while (0)
348#define debug_printf_varexp(...) do {} while (0)
349#define debug_printf_glob(...) do {} while (0)
350#define debug_printf_list(...) do {} while (0)
351#define debug_printf_subst(...) do {} while (0)
352#define debug_printf_clean(...) do {} while (0)
353
354#define ERR_PTR ((void*)(long)1)
355
356#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
357
358#define _SPECIAL_VARS_STR "_*@$!?#"
359#define SPECIAL_VARS_STR ("_*@$!?#" + 1)
360#define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
361#if ENABLE_HUSH_BASH_COMPAT
362/* Support / and // replace ops */
363/* Note that // is stored as \ in "encoded" string representation */
364# define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
365# define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
366# define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
367#else
368# define VAR_ENCODED_SUBST_OPS "%#:-=+?"
369# define VAR_SUBST_OPS "%#:-=+?"
370# define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
371#endif
372
373#define SPECIAL_VAR_SYMBOL 3
374
375struct variable;
376
377static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
378
379/* This supports saving pointers malloced in vfork child,
380 * to be freed in the parent.
381 */
382#if !BB_MMU
383typedef struct nommu_save_t {
384 char **new_env;
385 struct variable *old_vars;
386 char **argv;
387 char **argv_from_re_execing;
388} nommu_save_t;
389#endif
390
391enum {
392 RES_NONE = 0,
393#if ENABLE_HUSH_IF
394 RES_IF ,
395 RES_THEN ,
396 RES_ELIF ,
397 RES_ELSE ,
398 RES_FI ,
399#endif
400#if ENABLE_HUSH_LOOPS
401 RES_FOR ,
402 RES_WHILE ,
403 RES_UNTIL ,
404 RES_DO ,
405 RES_DONE ,
406#endif
407#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
408 RES_IN ,
409#endif
410#if ENABLE_HUSH_CASE
411 RES_CASE ,
412 /* three pseudo-keywords support contrived "case" syntax: */
413 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
414 RES_MATCH , /* "word)" */
415 RES_CASE_BODY, /* "this command is inside CASE" */
416 RES_ESAC ,
417#endif
418 RES_XXXX ,
419 RES_SNTX
420};
421
422typedef struct o_string {
423 char *data;
424 int length; /* position where data is appended */
425 int maxlen;
426 int o_expflags;
427 /* At least some part of the string was inside '' or "",
428 * possibly empty one: word"", wo''rd etc. */
429 smallint has_quoted_part;
430 smallint has_empty_slot;
431 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
432} o_string;
433enum {
434 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
435 EXP_FLAG_GLOB = 0x2,
436 /* Protect newly added chars against globbing
437 * by prepending \ to *, ?, [, \ */
438 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
439};
440enum {
441 MAYBE_ASSIGNMENT = 0,
442 DEFINITELY_ASSIGNMENT = 1,
443 NOT_ASSIGNMENT = 2,
444 /* Not an assigment, but next word may be: "if v=xyz cmd;" */
445 WORD_IS_KEYWORD = 3,
446};
447/* Used for initialization: o_string foo = NULL_O_STRING; */
448#define NULL_O_STRING { NULL }
449
450#ifndef debug_printf_parse
451static const char *const assignment_flag[] = {
452 "MAYBE_ASSIGNMENT",
453 "DEFINITELY_ASSIGNMENT",
454 "NOT_ASSIGNMENT",
455 "WORD_IS_KEYWORD",
456};
457#endif
458
459typedef struct in_str {
460 const char *p;
461 /* eof_flag=1: last char in ->p is really an EOF */
462 char eof_flag; /* meaningless if ->p == NULL */
463 char peek_buf[2];
464#if ENABLE_HUSH_INTERACTIVE
465 smallint promptmode; /* 0: PS1, 1: PS2 */
466#endif
467 int last_char;
468 FILE *file;
469 int (*get) (struct in_str *) FAST_FUNC;
470 int (*peek) (struct in_str *) FAST_FUNC;
471} in_str;
472#define i_getch(input) ((input)->get(input))
473#define i_peek(input) ((input)->peek(input))
474
475/* The descrip member of this structure is only used to make
476 * debugging output pretty */
477static const struct {
478 int mode;
479 signed char default_fd;
480 char descrip[3];
481} redir_table[] = {
482 { O_RDONLY, 0, "<" },
483 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
484 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
485 { O_CREAT|O_RDWR, 1, "<>" },
486 { O_RDONLY, 0, "<<" },
487/* Should not be needed. Bogus default_fd helps in debugging */
488/* { O_RDONLY, 77, "<<" }, */
489};
490
491struct redir_struct {
492 struct redir_struct *next;
493 char *rd_filename; /* filename */
494 int rd_fd; /* fd to redirect */
495 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
496 int rd_dup;
497 smallint rd_type; /* (enum redir_type) */
498 /* note: for heredocs, rd_filename contains heredoc delimiter,
499 * and subsequently heredoc itself; and rd_dup is a bitmask:
500 * bit 0: do we need to trim leading tabs?
501 * bit 1: is heredoc quoted (<<'delim' syntax) ?
502 */
503};
504typedef enum redir_type {
505 REDIRECT_INPUT = 0,
506 REDIRECT_OVERWRITE = 1,
507 REDIRECT_APPEND = 2,
508 REDIRECT_IO = 3,
509 REDIRECT_HEREDOC = 4,
510 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
511
512 REDIRFD_CLOSE = -3,
513 REDIRFD_SYNTAX_ERR = -2,
514 REDIRFD_TO_FILE = -1,
515 /* otherwise, rd_fd is redirected to rd_dup */
516
517 HEREDOC_SKIPTABS = 1,
518 HEREDOC_QUOTED = 2,
519} redir_type;
520
521
522struct command {
523 pid_t pid; /* 0 if exited */
524 int assignment_cnt; /* how many argv[i] are assignments? */
525 smallint cmd_type; /* CMD_xxx */
526#define CMD_NORMAL 0
527#define CMD_SUBSHELL 1
528#if ENABLE_HUSH_BASH_COMPAT
529/* used for "[[ EXPR ]]" */
530# define CMD_SINGLEWORD_NOGLOB 2
531#endif
532#if ENABLE_HUSH_FUNCTIONS
533# define CMD_FUNCDEF 3
534#endif
535
536 smalluint cmd_exitcode;
537 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
538 struct pipe *group;
539#if !BB_MMU
540 char *group_as_string;
541#endif
542#if ENABLE_HUSH_FUNCTIONS
543 struct function *child_func;
544/* This field is used to prevent a bug here:
545 * while...do f1() {a;}; f1; f1() {b;}; f1; done
546 * When we execute "f1() {a;}" cmd, we create new function and clear
547 * cmd->group, cmd->group_as_string, cmd->argv[0].
548 * When we execute "f1() {b;}", we notice that f1 exists,
549 * and that its "parent cmd" struct is still "alive",
550 * we put those fields back into cmd->xxx
551 * (struct function has ->parent_cmd ptr to facilitate that).
552 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
553 * Without this trick, loop would execute a;b;b;b;...
554 * instead of correct sequence a;b;a;b;...
555 * When command is freed, it severs the link
556 * (sets ->child_func->parent_cmd to NULL).
557 */
558#endif
559 char **argv; /* command name and arguments */
560/* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
561 * and on execution these are substituted with their values.
562 * Substitution can make _several_ words out of one argv[n]!
563 * Example: argv[0]=='.^C*^C.' here: echo .$*.
564 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
565 */
566 struct redir_struct *redirects; /* I/O redirections */
567};
568/* Is there anything in this command at all? */
569#define IS_NULL_CMD(cmd) \
570 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
571
572struct pipe {
573 struct pipe *next;
574 int num_cmds; /* total number of commands in pipe */
575 int alive_cmds; /* number of commands running (not exited) */
576 int stopped_cmds; /* number of commands alive, but stopped */
577#if ENABLE_HUSH_JOB
578 int jobid; /* job number */
579 pid_t pgrp; /* process group ID for the job */
580 char *cmdtext; /* name of job */
581#endif
582 struct command *cmds; /* array of commands in pipe */
583 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
584 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
585 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
586};
587typedef enum pipe_style {
588 PIPE_SEQ = 1,
589 PIPE_AND = 2,
590 PIPE_OR = 3,
591 PIPE_BG = 4,
592} pipe_style;
593/* Is there anything in this pipe at all? */
594#define IS_NULL_PIPE(pi) \
595 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
596
597/* This holds pointers to the various results of parsing */
598struct parse_context {
599 /* linked list of pipes */
600 struct pipe *list_head;
601 /* last pipe (being constructed right now) */
602 struct pipe *pipe;
603 /* last command in pipe (being constructed right now) */
604 struct command *command;
605 /* last redirect in command->redirects list */
606 struct redir_struct *pending_redirect;
607#if !BB_MMU
608 o_string as_string;
609#endif
610#if HAS_KEYWORDS
611 smallint ctx_res_w;
612 smallint ctx_inverted; /* "! cmd | cmd" */
613#if ENABLE_HUSH_CASE
614 smallint ctx_dsemicolon; /* ";;" seen */
615#endif
616 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
617 int old_flag;
618 /* group we are enclosed in:
619 * example: "if pipe1; pipe2; then pipe3; fi"
620 * when we see "if" or "then", we malloc and copy current context,
621 * and make ->stack point to it. then we parse pipeN.
622 * when closing "then" / fi" / whatever is found,
623 * we move list_head into ->stack->command->group,
624 * copy ->stack into current context, and delete ->stack.
625 * (parsing of { list } and ( list ) doesn't use this method)
626 */
627 struct parse_context *stack;
628#endif
629};
630
631/* On program start, environ points to initial environment.
632 * putenv adds new pointers into it, unsetenv removes them.
633 * Neither of these (de)allocates the strings.
634 * setenv allocates new strings in malloc space and does putenv,
635 * and thus setenv is unusable (leaky) for shell's purposes */
636#define setenv(...) setenv_is_leaky_dont_use()
637struct variable {
638 struct variable *next;
639 char *varstr; /* points to "name=" portion */
640#if ENABLE_HUSH_LOCAL
641 unsigned func_nest_level;
642#endif
643 int max_len; /* if > 0, name is part of initial env; else name is malloced */
644 smallint flg_export; /* putenv should be done on this var */
645 smallint flg_read_only;
646};
647
648enum {
649 BC_BREAK = 1,
650 BC_CONTINUE = 2,
651};
652
653#if ENABLE_HUSH_FUNCTIONS
654struct function {
655 struct function *next;
656 char *name;
657 struct command *parent_cmd;
658 struct pipe *body;
659# if !BB_MMU
660 char *body_as_string;
661# endif
662};
663#endif
664
665
666/* set -/+o OPT support. (TODO: make it optional)
667 * bash supports the following opts:
668 * allexport off
669 * braceexpand on
670 * emacs on
671 * errexit off
672 * errtrace off
673 * functrace off
674 * hashall on
675 * histexpand off
676 * history on
677 * ignoreeof off
678 * interactive-comments on
679 * keyword off
680 * monitor on
681 * noclobber off
682 * noexec off
683 * noglob off
684 * nolog off
685 * notify off
686 * nounset off
687 * onecmd off
688 * physical off
689 * pipefail off
690 * posix off
691 * privileged off
692 * verbose off
693 * vi off
694 * xtrace off
695 */
696static const char o_opt_strings[] ALIGN1 =
697 "pipefail\0"
698 "noexec\0"
699#if ENABLE_HUSH_MODE_X
700 "xtrace\0"
701#endif
702 ;
703enum {
704 OPT_O_PIPEFAIL,
705 OPT_O_NOEXEC,
706#if ENABLE_HUSH_MODE_X
707 OPT_O_XTRACE,
708#endif
709 NUM_OPT_O
710};
711
712
713/* "Globals" within this file */
714/* Sorted roughly by size (smaller offsets == smaller code) */
715struct globals {
716 /* interactive_fd != 0 means we are an interactive shell.
717 * If we are, then saved_tty_pgrp can also be != 0, meaning
718 * that controlling tty is available. With saved_tty_pgrp == 0,
719 * job control still works, but terminal signals
720 * (^C, ^Z, ^Y, ^\) won't work at all, and background
721 * process groups can only be created with "cmd &".
722 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
723 * to give tty to the foreground process group,
724 * and will take it back when the group is stopped (^Z)
725 * or killed (^C).
726 */
727#if ENABLE_HUSH_INTERACTIVE
728 /* 'interactive_fd' is a fd# open to ctty, if we have one
729 * _AND_ if we decided to act interactively */
730 int interactive_fd;
731 const char *PS1;
732 const char *PS2;
733# define G_interactive_fd (G.interactive_fd)
734#else
735# define G_interactive_fd 0
736#endif
737#if ENABLE_FEATURE_EDITING
738 line_input_t *line_input_state;
739#endif
740 pid_t root_pid;
741 pid_t root_ppid;
742 pid_t last_bg_pid;
743#if ENABLE_HUSH_RANDOM_SUPPORT
744 random_t random_gen;
745#endif
746#if ENABLE_HUSH_JOB
747 int run_list_level;
748 int last_jobid;
749 pid_t saved_tty_pgrp;
750 struct pipe *job_list;
751# define G_saved_tty_pgrp (G.saved_tty_pgrp)
752#else
753# define G_saved_tty_pgrp 0
754#endif
755 char o_opt[NUM_OPT_O];
756#if ENABLE_HUSH_MODE_X
757# define G_x_mode (G.o_opt[OPT_O_XTRACE])
758#else
759# define G_x_mode 0
760#endif
761 smallint flag_SIGINT;
762#if ENABLE_HUSH_LOOPS
763 smallint flag_break_continue;
764#endif
765#if ENABLE_HUSH_FUNCTIONS
766 /* 0: outside of a function (or sourced file)
767 * -1: inside of a function, ok to use return builtin
768 * 1: return is invoked, skip all till end of func
769 */
770 smallint flag_return_in_progress;
771#endif
772 smallint exiting; /* used to prevent EXIT trap recursion */
773 /* These four support $?, $#, and $1 */
774 smalluint last_exitcode;
775 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
776 smalluint global_args_malloced;
777 /* how many non-NULL argv's we have. NB: $# + 1 */
778 int global_argc;
779 char **global_argv;
780#if !BB_MMU
781 char *argv0_for_re_execing;
782#endif
783#if ENABLE_HUSH_LOOPS
784 unsigned depth_break_continue;
785 unsigned depth_of_loop;
786#endif
787 const char *ifs;
788 const char *cwd;
789 struct variable *top_var;
790 char **expanded_assignments;
791#if ENABLE_HUSH_FUNCTIONS
792 struct function *top_func;
793# if ENABLE_HUSH_LOCAL
794 struct variable **shadowed_vars_pp;
795 unsigned func_nest_level;
796# endif
797#endif
798 /* Signal and trap handling */
799#if ENABLE_HUSH_FAST
800 unsigned count_SIGCHLD;
801 unsigned handled_SIGCHLD;
802 smallint we_have_children;
803#endif
804 /* Which signals have non-DFL handler (even with no traps set)?
805 * Set at the start to:
806 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
807 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
808 * The rest is cleared right before execv syscalls.
809 * Other than these two times, never modified.
810 */
811 unsigned special_sig_mask;
812#if ENABLE_HUSH_JOB
813 unsigned fatal_sig_mask;
814# define G_fatal_sig_mask G.fatal_sig_mask
815#else
816# define G_fatal_sig_mask 0
817#endif
818 char **traps; /* char *traps[NSIG] */
819 sigset_t pending_set;
820#if HUSH_DEBUG
821 unsigned long memleak_value;
822 int debug_indent;
823#endif
824 struct sigaction sa;
825 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
826};
827#define G (*ptr_to_globals)
828/* Not #defining name to G.name - this quickly gets unwieldy
829 * (too many defines). Also, I actually prefer to see when a variable
830 * is global, thus "G." prefix is a useful hint */
831#define INIT_G() do { \
832 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
833 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
834 sigfillset(&G.sa.sa_mask); \
835 G.sa.sa_flags = SA_RESTART; \
836} while (0)
837
838
839/* Function prototypes for builtins */
840static int builtin_cd(char **argv) FAST_FUNC;
841static int builtin_echo(char **argv) FAST_FUNC;
842static int builtin_eval(char **argv) FAST_FUNC;
843static int builtin_exec(char **argv) FAST_FUNC;
844static int builtin_exit(char **argv) FAST_FUNC;
845static int builtin_export(char **argv) FAST_FUNC;
846#if ENABLE_HUSH_JOB
847static int builtin_fg_bg(char **argv) FAST_FUNC;
848static int builtin_jobs(char **argv) FAST_FUNC;
849#endif
850#if ENABLE_HUSH_HELP
851static int builtin_help(char **argv) FAST_FUNC;
852#endif
853#if MAX_HISTORY && ENABLE_FEATURE_EDITING
854static int builtin_history(char **argv) FAST_FUNC;
855#endif
856#if ENABLE_HUSH_LOCAL
857static int builtin_local(char **argv) FAST_FUNC;
858#endif
859#if HUSH_DEBUG
860static int builtin_memleak(char **argv) FAST_FUNC;
861#endif
862#if ENABLE_PRINTF
863static int builtin_printf(char **argv) FAST_FUNC;
864#endif
865static int builtin_pwd(char **argv) FAST_FUNC;
866static int builtin_read(char **argv) FAST_FUNC;
867static int builtin_set(char **argv) FAST_FUNC;
868static int builtin_shift(char **argv) FAST_FUNC;
869static int builtin_source(char **argv) FAST_FUNC;
870static int builtin_test(char **argv) FAST_FUNC;
871static int builtin_trap(char **argv) FAST_FUNC;
872static int builtin_type(char **argv) FAST_FUNC;
873static int builtin_true(char **argv) FAST_FUNC;
874static int builtin_umask(char **argv) FAST_FUNC;
875static int builtin_unset(char **argv) FAST_FUNC;
876static int builtin_wait(char **argv) FAST_FUNC;
877#if ENABLE_HUSH_LOOPS
878static int builtin_break(char **argv) FAST_FUNC;
879static int builtin_continue(char **argv) FAST_FUNC;
880#endif
881#if ENABLE_HUSH_FUNCTIONS
882static int builtin_return(char **argv) FAST_FUNC;
883#endif
884
885/* Table of built-in functions. They can be forked or not, depending on
886 * context: within pipes, they fork. As simple commands, they do not.
887 * When used in non-forking context, they can change global variables
888 * in the parent shell process. If forked, of course they cannot.
889 * For example, 'unset foo | whatever' will parse and run, but foo will
890 * still be set at the end. */
891struct built_in_command {
892 const char *b_cmd;
893 int (*b_function)(char **argv) FAST_FUNC;
894#if ENABLE_HUSH_HELP
895 const char *b_descr;
896# define BLTIN(cmd, func, help) { cmd, func, help }
897#else
898# define BLTIN(cmd, func, help) { cmd, func }
899#endif
900};
901
902static const struct built_in_command bltins1[] = {
903 BLTIN("." , builtin_source , "Run commands in a file"),
904 BLTIN(":" , builtin_true , NULL),
905#if ENABLE_HUSH_JOB
906 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
907#endif
908#if ENABLE_HUSH_LOOPS
909 BLTIN("break" , builtin_break , "Exit from a loop"),
910#endif
911 BLTIN("cd" , builtin_cd , "Change directory"),
912#if ENABLE_HUSH_LOOPS
913 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
914#endif
915 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
916 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
917 BLTIN("exit" , builtin_exit , "Exit"),
918 BLTIN("export" , builtin_export , "Set environment variables"),
919#if ENABLE_HUSH_JOB
920 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
921#endif
922#if ENABLE_HUSH_HELP
923 BLTIN("help" , builtin_help , NULL),
924#endif
925#if MAX_HISTORY && ENABLE_FEATURE_EDITING
926 BLTIN("history" , builtin_history , "Show command history"),
927#endif
928#if ENABLE_HUSH_JOB
929 BLTIN("jobs" , builtin_jobs , "List jobs"),
930#endif
931#if ENABLE_HUSH_LOCAL
932 BLTIN("local" , builtin_local , "Set local variables"),
933#endif
934#if HUSH_DEBUG
935 BLTIN("memleak" , builtin_memleak , NULL),
936#endif
937 BLTIN("read" , builtin_read , "Input into variable"),
938#if ENABLE_HUSH_FUNCTIONS
939 BLTIN("return" , builtin_return , "Return from a function"),
940#endif
941 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
942 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
943#if ENABLE_HUSH_BASH_COMPAT
944 BLTIN("source" , builtin_source , "Run commands in a file"),
945#endif
946 BLTIN("trap" , builtin_trap , "Trap signals"),
947 BLTIN("type" , builtin_type , "Show command type"),
948 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
949 BLTIN("umask" , builtin_umask , "Set file creation mask"),
950 BLTIN("unset" , builtin_unset , "Unset variables"),
951 BLTIN("wait" , builtin_wait , "Wait for process"),
952};
953/* For now, echo and test are unconditionally enabled.
954 * Maybe make it configurable? */
955static const struct built_in_command bltins2[] = {
956 BLTIN("[" , builtin_test , NULL),
957 BLTIN("echo" , builtin_echo , NULL),
958#if ENABLE_PRINTF
959 BLTIN("printf" , builtin_printf , NULL),
960#endif
961 BLTIN("pwd" , builtin_pwd , NULL),
962 BLTIN("test" , builtin_test , NULL),
963};
964
965
966/* Debug printouts.
967 */
968#if HUSH_DEBUG
969/* prevent disasters with G.debug_indent < 0 */
970# define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
971# define debug_enter() (G.debug_indent++)
972# define debug_leave() (G.debug_indent--)
973#else
974# define indent() ((void)0)
975# define debug_enter() ((void)0)
976# define debug_leave() ((void)0)
977#endif
978
979#ifndef debug_printf
980# define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
981#endif
982
983#ifndef debug_printf_parse
984# define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
985#endif
986
987#ifndef debug_printf_exec
988#define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
989#endif
990
991#ifndef debug_printf_env
992# define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
993#endif
994
995#ifndef debug_printf_jobs
996# define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
997# define DEBUG_JOBS 1
998#else
999# define DEBUG_JOBS 0
1000#endif
1001
1002#ifndef debug_printf_expand
1003# define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1004# define DEBUG_EXPAND 1
1005#else
1006# define DEBUG_EXPAND 0
1007#endif
1008
1009#ifndef debug_printf_varexp
1010# define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1011#endif
1012
1013#ifndef debug_printf_glob
1014# define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1015# define DEBUG_GLOB 1
1016#else
1017# define DEBUG_GLOB 0
1018#endif
1019
1020#ifndef debug_printf_list
1021# define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1022#endif
1023
1024#ifndef debug_printf_subst
1025# define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1026#endif
1027
1028#ifndef debug_printf_clean
1029# define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1030# define DEBUG_CLEAN 1
1031#else
1032# define DEBUG_CLEAN 0
1033#endif
1034
1035#if DEBUG_EXPAND
1036static void debug_print_strings(const char *prefix, char **vv)
1037{
1038 indent();
1039 fdprintf(2, "%s:\n", prefix);
1040 while (*vv)
1041 fdprintf(2, " '%s'\n", *vv++);
1042}
1043#else
1044# define debug_print_strings(prefix, vv) ((void)0)
1045#endif
1046
1047
1048/* Leak hunting. Use hush_leaktool.sh for post-processing.
1049 */
1050#if LEAK_HUNTING
1051static void *xxmalloc(int lineno, size_t size)
1052{
1053 void *ptr = xmalloc((size + 0xff) & ~0xff);
1054 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1055 return ptr;
1056}
1057static void *xxrealloc(int lineno, void *ptr, size_t size)
1058{
1059 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1060 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1061 return ptr;
1062}
1063static char *xxstrdup(int lineno, const char *str)
1064{
1065 char *ptr = xstrdup(str);
1066 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1067 return ptr;
1068}
1069static void xxfree(void *ptr)
1070{
1071 fdprintf(2, "free %p\n", ptr);
1072 free(ptr);
1073}
1074# define xmalloc(s) xxmalloc(__LINE__, s)
1075# define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1076# define xstrdup(s) xxstrdup(__LINE__, s)
1077# define free(p) xxfree(p)
1078#endif
1079
1080
1081/* Syntax and runtime errors. They always abort scripts.
1082 * In interactive use they usually discard unparsed and/or unexecuted commands
1083 * and return to the prompt.
1084 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1085 */
1086#if HUSH_DEBUG < 2
1087# define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1088# define syntax_error(lineno, msg) syntax_error(msg)
1089# define syntax_error_at(lineno, msg) syntax_error_at(msg)
1090# define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1091# define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1092# define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1093#endif
1094
1095static void die_if_script(unsigned lineno, const char *fmt, ...)
1096{
1097 va_list p;
1098
1099#if HUSH_DEBUG >= 2
1100 bb_error_msg("hush.c:%u", lineno);
1101#endif
1102 va_start(p, fmt);
1103 bb_verror_msg(fmt, p, NULL);
1104 va_end(p);
1105 if (!G_interactive_fd)
1106 xfunc_die();
1107}
1108
1109static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1110{
1111 if (msg)
1112 bb_error_msg("syntax error: %s", msg);
1113 else
1114 bb_error_msg("syntax error");
1115}
1116
1117static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1118{
1119 bb_error_msg("syntax error at '%s'", msg);
1120}
1121
1122static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1123{
1124 bb_error_msg("syntax error: unterminated %s", s);
1125}
1126
1127static void syntax_error_unterm_ch(unsigned lineno, char ch)
1128{
1129 char msg[2] = { ch, '\0' };
1130 syntax_error_unterm_str(lineno, msg);
1131}
1132
1133static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1134{
1135 char msg[2];
1136 msg[0] = ch;
1137 msg[1] = '\0';
1138 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1139}
1140
1141#if HUSH_DEBUG < 2
1142# undef die_if_script
1143# undef syntax_error
1144# undef syntax_error_at
1145# undef syntax_error_unterm_ch
1146# undef syntax_error_unterm_str
1147# undef syntax_error_unexpected_ch
1148#else
1149# define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1150# define syntax_error(msg) syntax_error(__LINE__, msg)
1151# define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1152# define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1153# define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1154# define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1155#endif
1156
1157
1158#if ENABLE_HUSH_INTERACTIVE
1159static void cmdedit_update_prompt(void);
1160#else
1161# define cmdedit_update_prompt() ((void)0)
1162#endif
1163
1164
1165/* Utility functions
1166 */
1167/* Replace each \x with x in place, return ptr past NUL. */
1168static char *unbackslash(char *src)
1169{
1170 char *dst = src = strchrnul(src, '\\');
1171 while (1) {
1172 if (*src == '\\')
1173 src++;
1174 if ((*dst++ = *src++) == '\0')
1175 break;
1176 }
1177 return dst;
1178}
1179
1180static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1181{
1182 int i;
1183 unsigned count1;
1184 unsigned count2;
1185 char **v;
1186
1187 v = strings;
1188 count1 = 0;
1189 if (v) {
1190 while (*v) {
1191 count1++;
1192 v++;
1193 }
1194 }
1195 count2 = 0;
1196 v = add;
1197 while (*v) {
1198 count2++;
1199 v++;
1200 }
1201 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1202 v[count1 + count2] = NULL;
1203 i = count2;
1204 while (--i >= 0)
1205 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1206 return v;
1207}
1208#if LEAK_HUNTING
1209static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1210{
1211 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1212 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1213 return ptr;
1214}
1215#define add_strings_to_strings(strings, add, need_to_dup) \
1216 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1217#endif
1218
1219/* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1220static char **add_string_to_strings(char **strings, char *add)
1221{
1222 char *v[2];
1223 v[0] = add;
1224 v[1] = NULL;
1225 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1226}
1227#if LEAK_HUNTING
1228static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1229{
1230 char **ptr = add_string_to_strings(strings, add);
1231 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1232 return ptr;
1233}
1234#define add_string_to_strings(strings, add) \
1235 xx_add_string_to_strings(__LINE__, strings, add)
1236#endif
1237
1238static void free_strings(char **strings)
1239{
1240 char **v;
1241
1242 if (!strings)
1243 return;
1244 v = strings;
1245 while (*v) {
1246 free(*v);
1247 v++;
1248 }
1249 free(strings);
1250}
1251
1252
1253/* Helpers for setting new $n and restoring them back
1254 */
1255typedef struct save_arg_t {
1256 char *sv_argv0;
1257 char **sv_g_argv;
1258 int sv_g_argc;
1259 smallint sv_g_malloced;
1260} save_arg_t;
1261
1262static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1263{
1264 int n;
1265
1266 sv->sv_argv0 = argv[0];
1267 sv->sv_g_argv = G.global_argv;
1268 sv->sv_g_argc = G.global_argc;
1269 sv->sv_g_malloced = G.global_args_malloced;
1270
1271 argv[0] = G.global_argv[0]; /* retain $0 */
1272 G.global_argv = argv;
1273 G.global_args_malloced = 0;
1274
1275 n = 1;
1276 while (*++argv)
1277 n++;
1278 G.global_argc = n;
1279}
1280
1281static void restore_G_args(save_arg_t *sv, char **argv)
1282{
1283 char **pp;
1284
1285 if (G.global_args_malloced) {
1286 /* someone ran "set -- arg1 arg2 ...", undo */
1287 pp = G.global_argv;
1288 while (*++pp) /* note: does not free $0 */
1289 free(*pp);
1290 free(G.global_argv);
1291 }
1292 argv[0] = sv->sv_argv0;
1293 G.global_argv = sv->sv_g_argv;
1294 G.global_argc = sv->sv_g_argc;
1295 G.global_args_malloced = sv->sv_g_malloced;
1296}
1297
1298
1299/* Basic theory of signal handling in shell
1300 * ========================================
1301 * This does not describe what hush does, rather, it is current understanding
1302 * what it _should_ do. If it doesn't, it's a bug.
1303 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1304 *
1305 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1306 * is finished or backgrounded. It is the same in interactive and
1307 * non-interactive shells, and is the same regardless of whether
1308 * a user trap handler is installed or a shell special one is in effect.
1309 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1310 * backgrounds (i.e. stops) or kills all members of currently running
1311 * pipe.
1312 *
1313 * Wait builtin is interruptible by signals for which user trap is set
1314 * or by SIGINT in interactive shell.
1315 *
1316 * Trap handlers will execute even within trap handlers. (right?)
1317 *
1318 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1319 * except for handlers set to '' (empty string).
1320 *
1321 * If job control is off, backgrounded commands ("cmd &")
1322 * have SIGINT, SIGQUIT set to SIG_IGN.
1323 *
1324 * Commands which are run in command substitution ("`cmd`")
1325 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1326 *
1327 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1328 * by the shell from its parent.
1329 *
1330 * Signals which differ from SIG_DFL action
1331 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1332 *
1333 * SIGQUIT: ignore
1334 * SIGTERM (interactive): ignore
1335 * SIGHUP (interactive):
1336 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1337 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1338 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1339 * that all pipe members are stopped. Try this in bash:
1340 * while :; do :; done - ^Z does not background it
1341 * (while :; do :; done) - ^Z backgrounds it
1342 * SIGINT (interactive): wait for last pipe, ignore the rest
1343 * of the command line, show prompt. NB: ^C does not send SIGINT
1344 * to interactive shell while shell is waiting for a pipe,
1345 * since shell is bg'ed (is not in foreground process group).
1346 * Example 1: this waits 5 sec, but does not execute ls:
1347 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1348 * Example 2: this does not wait and does not execute ls:
1349 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1350 * Example 3: this does not wait 5 sec, but executes ls:
1351 * "sleep 5; ls -l" + press ^C
1352 * Example 4: this does not wait and does not execute ls:
1353 * "sleep 5 & wait; ls -l" + press ^C
1354 *
1355 * (What happens to signals which are IGN on shell start?)
1356 * (What happens with signal mask on shell start?)
1357 *
1358 * Old implementation
1359 * ==================
1360 * We use in-kernel pending signal mask to determine which signals were sent.
1361 * We block all signals which we don't want to take action immediately,
1362 * i.e. we block all signals which need to have special handling as described
1363 * above, and all signals which have traps set.
1364 * After each pipe execution, we extract any pending signals via sigtimedwait()
1365 * and act on them.
1366 *
1367 * unsigned special_sig_mask: a mask of such "special" signals
1368 * sigset_t blocked_set: current blocked signal set
1369 *
1370 * "trap - SIGxxx":
1371 * clear bit in blocked_set unless it is also in special_sig_mask
1372 * "trap 'cmd' SIGxxx":
1373 * set bit in blocked_set (even if 'cmd' is '')
1374 * after [v]fork, if we plan to be a shell:
1375 * unblock signals with special interactive handling
1376 * (child shell is not interactive),
1377 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1378 * after [v]fork, if we plan to exec:
1379 * POSIX says fork clears pending signal mask in child - no need to clear it.
1380 * Restore blocked signal set to one inherited by shell just prior to exec.
1381 *
1382 * Note: as a result, we do not use signal handlers much. The only uses
1383 * are to count SIGCHLDs
1384 * and to restore tty pgrp on signal-induced exit.
1385 *
1386 * Note 2 (compat):
1387 * Standard says "When a subshell is entered, traps that are not being ignored
1388 * are set to the default actions". bash interprets it so that traps which
1389 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1390 *
1391 * Problem: the above approach makes it unwieldy to catch signals while
1392 * we are in read builtin, or while we read commands from stdin:
1393 * masked signals are not visible!
1394 *
1395 * New implementation
1396 * ==================
1397 * We record each signal we are interested in by installing signal handler
1398 * for them - a bit like emulating kernel pending signal mask in userspace.
1399 * We are interested in: signals which need to have special handling
1400 * as described above, and all signals which have traps set.
1401 * Signals are recorded in pending_set.
1402 * After each pipe execution, we extract any pending signals
1403 * and act on them.
1404 *
1405 * unsigned special_sig_mask: a mask of shell-special signals.
1406 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1407 * char *traps[sig] if trap for sig is set (even if it's '').
1408 * sigset_t pending_set: set of sigs we received.
1409 *
1410 * "trap - SIGxxx":
1411 * if sig is in special_sig_mask, set handler back to:
1412 * record_pending_signo, or to IGN if it's a tty stop signal
1413 * if sig is in fatal_sig_mask, set handler back to sigexit.
1414 * else: set handler back to SIG_DFL
1415 * "trap 'cmd' SIGxxx":
1416 * set handler to record_pending_signo.
1417 * "trap '' SIGxxx":
1418 * set handler to SIG_IGN.
1419 * after [v]fork, if we plan to be a shell:
1420 * set signals with special interactive handling to SIG_DFL
1421 * (because child shell is not interactive),
1422 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1423 * after [v]fork, if we plan to exec:
1424 * POSIX says fork clears pending signal mask in child - no need to clear it.
1425 *
1426 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1427 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1428 *
1429 * Note (compat):
1430 * Standard says "When a subshell is entered, traps that are not being ignored
1431 * are set to the default actions". bash interprets it so that traps which
1432 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1433 */
1434enum {
1435 SPECIAL_INTERACTIVE_SIGS = 0
1436 | (1 << SIGTERM)
1437 | (1 << SIGINT)
1438 | (1 << SIGHUP)
1439 ,
1440 SPECIAL_JOBSTOP_SIGS = 0
1441#if ENABLE_HUSH_JOB
1442 | (1 << SIGTTIN)
1443 | (1 << SIGTTOU)
1444 | (1 << SIGTSTP)
1445#endif
1446 ,
1447};
1448
1449static void record_pending_signo(int sig)
1450{
1451 sigaddset(&G.pending_set, sig);
1452#if ENABLE_HUSH_FAST
1453 if (sig == SIGCHLD) {
1454 G.count_SIGCHLD++;
1455//bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1456 }
1457#endif
1458}
1459
1460static sighandler_t install_sighandler(int sig, sighandler_t handler)
1461{
1462 struct sigaction old_sa;
1463
1464 /* We could use signal() to install handlers... almost:
1465 * except that we need to mask ALL signals while handlers run.
1466 * I saw signal nesting in strace, race window isn't small.
1467 * SA_RESTART is also needed, but in Linux, signal()
1468 * sets SA_RESTART too.
1469 */
1470 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1471 /* sigfillset(&G.sa.sa_mask); - already done */
1472 /* G.sa.sa_flags = SA_RESTART; - already done */
1473 G.sa.sa_handler = handler;
1474 sigaction(sig, &G.sa, &old_sa);
1475 return old_sa.sa_handler;
1476}
1477
1478#if ENABLE_HUSH_JOB
1479
1480/* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1481# define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1482/* After [v]fork, in parent: restore tty pgrp on xfunc death */
1483# define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1484
1485/* Restores tty foreground process group, and exits.
1486 * May be called as signal handler for fatal signal
1487 * (will resend signal to itself, producing correct exit state)
1488 * or called directly with -EXITCODE.
1489 * We also call it if xfunc is exiting. */
1490static void sigexit(int sig) NORETURN;
1491static void sigexit(int sig)
1492{
1493 /* Careful: we can end up here after [v]fork. Do not restore
1494 * tty pgrp then, only top-level shell process does that */
1495 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1496 /* Disable all signals: job control, SIGPIPE, etc.
1497 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1498 */
1499 sigprocmask_allsigs(SIG_BLOCK);
1500 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1501 }
1502
1503 /* Not a signal, just exit */
1504 if (sig <= 0)
1505 _exit(- sig);
1506
1507 kill_myself_with_sig(sig); /* does not return */
1508}
1509#else
1510
1511# define disable_restore_tty_pgrp_on_exit() ((void)0)
1512# define enable_restore_tty_pgrp_on_exit() ((void)0)
1513
1514#endif
1515
1516static sighandler_t pick_sighandler(unsigned sig)
1517{
1518 sighandler_t handler = SIG_DFL;
1519 if (sig < sizeof(unsigned)*8) {
1520 unsigned sigmask = (1 << sig);
1521
1522#if ENABLE_HUSH_JOB
1523 /* is sig fatal? */
1524 if (G_fatal_sig_mask & sigmask)
1525 handler = sigexit;
1526 else
1527#endif
1528 /* sig has special handling? */
1529 if (G.special_sig_mask & sigmask) {
1530 handler = record_pending_signo;
1531 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1532 * in order to ignore them: they will be raised
1533 * in an endless loop when we try to do some
1534 * terminal ioctls! We do have to _ignore_ these.
1535 */
1536 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1537 handler = SIG_IGN;
1538 }
1539 }
1540 return handler;
1541}
1542
1543/* Restores tty foreground process group, and exits. */
1544static void hush_exit(int exitcode) NORETURN;
1545static void hush_exit(int exitcode)
1546{
1547#if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1548 save_history(G.line_input_state);
1549#endif
1550
1551 fflush_all();
1552 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1553 char *argv[3];
1554 /* argv[0] is unused */
1555 argv[1] = G.traps[0];
1556 argv[2] = NULL;
1557 G.exiting = 1; /* prevent EXIT trap recursion */
1558 /* Note: G.traps[0] is not cleared!
1559 * "trap" will still show it, if executed
1560 * in the handler */
1561 builtin_eval(argv);
1562 }
1563
1564#if ENABLE_FEATURE_CLEAN_UP
1565 {
1566 struct variable *cur_var;
1567 if (G.cwd != bb_msg_unknown)
1568 free((char*)G.cwd);
1569 cur_var = G.top_var;
1570 while (cur_var) {
1571 struct variable *tmp = cur_var;
1572 if (!cur_var->max_len)
1573 free(cur_var->varstr);
1574 cur_var = cur_var->next;
1575 free(tmp);
1576 }
1577 }
1578#endif
1579
1580#if ENABLE_HUSH_JOB
1581 fflush_all();
1582 sigexit(- (exitcode & 0xff));
1583#else
1584 exit(exitcode);
1585#endif
1586}
1587
1588
1589//TODO: return a mask of ALL handled sigs?
1590static int check_and_run_traps(void)
1591{
1592 int last_sig = 0;
1593
1594 while (1) {
1595 int sig;
1596
1597 if (sigisemptyset(&G.pending_set))
1598 break;
1599 sig = 0;
1600 do {
1601 sig++;
1602 if (sigismember(&G.pending_set, sig)) {
1603 sigdelset(&G.pending_set, sig);
1604 goto got_sig;
1605 }
1606 } while (sig < NSIG);
1607 break;
1608 got_sig:
1609 if (G.traps && G.traps[sig]) {
1610 if (G.traps[sig][0]) {
1611 /* We have user-defined handler */
1612 smalluint save_rcode;
1613 char *argv[3];
1614 /* argv[0] is unused */
1615 argv[1] = G.traps[sig];
1616 argv[2] = NULL;
1617 save_rcode = G.last_exitcode;
1618 builtin_eval(argv);
1619 G.last_exitcode = save_rcode;
1620 last_sig = sig;
1621 } /* else: "" trap, ignoring signal */
1622 continue;
1623 }
1624 /* not a trap: special action */
1625 switch (sig) {
1626 case SIGINT:
1627 /* Builtin was ^C'ed, make it look prettier: */
1628 bb_putchar('\n');
1629 G.flag_SIGINT = 1;
1630 last_sig = sig;
1631 break;
1632#if ENABLE_HUSH_JOB
1633 case SIGHUP: {
1634 struct pipe *job;
1635 /* bash is observed to signal whole process groups,
1636 * not individual processes */
1637 for (job = G.job_list; job; job = job->next) {
1638 if (job->pgrp <= 0)
1639 continue;
1640 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1641 if (kill(- job->pgrp, SIGHUP) == 0)
1642 kill(- job->pgrp, SIGCONT);
1643 }
1644 sigexit(SIGHUP);
1645 }
1646#endif
1647#if ENABLE_HUSH_FAST
1648 case SIGCHLD:
1649 G.count_SIGCHLD++;
1650//bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1651 /* Note:
1652 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1653 * This simplifies wait builtin a bit.
1654 */
1655 break;
1656#endif
1657 default: /* ignored: */
1658 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1659 /* Note:
1660 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1661 * Example: wait is not interrupted by TERM
1662 * in interactive shell, because TERM is ignored.
1663 */
1664 break;
1665 }
1666 }
1667 return last_sig;
1668}
1669
1670
1671static const char *get_cwd(int force)
1672{
1673 if (force || G.cwd == NULL) {
1674 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1675 * we must not try to free(bb_msg_unknown) */
1676 if (G.cwd == bb_msg_unknown)
1677 G.cwd = NULL;
1678 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1679 if (!G.cwd)
1680 G.cwd = bb_msg_unknown;
1681 }
1682 return G.cwd;
1683}
1684
1685
1686/*
1687 * Shell and environment variable support
1688 */
1689static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1690{
1691 struct variable **pp;
1692 struct variable *cur;
1693
1694 pp = &G.top_var;
1695 while ((cur = *pp) != NULL) {
1696 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1697 return pp;
1698 pp = &cur->next;
1699 }
1700 return NULL;
1701}
1702
1703static const char* FAST_FUNC get_local_var_value(const char *name)
1704{
1705 struct variable **vpp;
1706 unsigned len = strlen(name);
1707
1708 if (G.expanded_assignments) {
1709 char **cpp = G.expanded_assignments;
1710 while (*cpp) {
1711 char *cp = *cpp;
1712 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1713 return cp + len + 1;
1714 cpp++;
1715 }
1716 }
1717
1718 vpp = get_ptr_to_local_var(name, len);
1719 if (vpp)
1720 return (*vpp)->varstr + len + 1;
1721
1722 if (strcmp(name, "PPID") == 0)
1723 return utoa(G.root_ppid);
1724 // bash compat: UID? EUID?
1725#if ENABLE_HUSH_RANDOM_SUPPORT
1726 if (strcmp(name, "RANDOM") == 0)
1727 return utoa(next_random(&G.random_gen));
1728#endif
1729 return NULL;
1730}
1731
1732/* str holds "NAME=VAL" and is expected to be malloced.
1733 * We take ownership of it.
1734 * flg_export:
1735 * 0: do not change export flag
1736 * (if creating new variable, flag will be 0)
1737 * 1: set export flag and putenv the variable
1738 * -1: clear export flag and unsetenv the variable
1739 * flg_read_only is set only when we handle -R var=val
1740 */
1741#if !BB_MMU && ENABLE_HUSH_LOCAL
1742/* all params are used */
1743#elif BB_MMU && ENABLE_HUSH_LOCAL
1744#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1745 set_local_var(str, flg_export, local_lvl)
1746#elif BB_MMU && !ENABLE_HUSH_LOCAL
1747#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1748 set_local_var(str, flg_export)
1749#elif !BB_MMU && !ENABLE_HUSH_LOCAL
1750#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1751 set_local_var(str, flg_export, flg_read_only)
1752#endif
1753static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1754{
1755 struct variable **var_pp;
1756 struct variable *cur;
1757 char *eq_sign;
1758 int name_len;
1759
1760 eq_sign = strchr(str, '=');
1761 if (!eq_sign) { /* not expected to ever happen? */
1762 free(str);
1763 return -1;
1764 }
1765
1766 name_len = eq_sign - str + 1; /* including '=' */
1767 var_pp = &G.top_var;
1768 while ((cur = *var_pp) != NULL) {
1769 if (strncmp(cur->varstr, str, name_len) != 0) {
1770 var_pp = &cur->next;
1771 continue;
1772 }
1773 /* We found an existing var with this name */
1774 if (cur->flg_read_only) {
1775#if !BB_MMU
1776 if (!flg_read_only)
1777#endif
1778 bb_error_msg("%s: readonly variable", str);
1779 free(str);
1780 return -1;
1781 }
1782 if (flg_export == -1) { // "&& cur->flg_export" ?
1783 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1784 *eq_sign = '\0';
1785 unsetenv(str);
1786 *eq_sign = '=';
1787 }
1788#if ENABLE_HUSH_LOCAL
1789 if (cur->func_nest_level < local_lvl) {
1790 /* New variable is declared as local,
1791 * and existing one is global, or local
1792 * from enclosing function.
1793 * Remove and save old one: */
1794 *var_pp = cur->next;
1795 cur->next = *G.shadowed_vars_pp;
1796 *G.shadowed_vars_pp = cur;
1797 /* bash 3.2.33(1) and exported vars:
1798 * # export z=z
1799 * # f() { local z=a; env | grep ^z; }
1800 * # f
1801 * z=a
1802 * # env | grep ^z
1803 * z=z
1804 */
1805 if (cur->flg_export)
1806 flg_export = 1;
1807 break;
1808 }
1809#endif
1810 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1811 free_and_exp:
1812 free(str);
1813 goto exp;
1814 }
1815 if (cur->max_len != 0) {
1816 if (cur->max_len >= strlen(str)) {
1817 /* This one is from startup env, reuse space */
1818 strcpy(cur->varstr, str);
1819 goto free_and_exp;
1820 }
1821 } else {
1822 /* max_len == 0 signifies "malloced" var, which we can
1823 * (and has to) free */
1824 free(cur->varstr);
1825 }
1826 cur->max_len = 0;
1827 goto set_str_and_exp;
1828 }
1829
1830 /* Not found - create new variable struct */
1831 cur = xzalloc(sizeof(*cur));
1832#if ENABLE_HUSH_LOCAL
1833 cur->func_nest_level = local_lvl;
1834#endif
1835 cur->next = *var_pp;
1836 *var_pp = cur;
1837
1838 set_str_and_exp:
1839 cur->varstr = str;
1840#if !BB_MMU
1841 cur->flg_read_only = flg_read_only;
1842#endif
1843 exp:
1844 if (flg_export == 1)
1845 cur->flg_export = 1;
1846 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1847 cmdedit_update_prompt();
1848 if (cur->flg_export) {
1849 if (flg_export == -1) {
1850 cur->flg_export = 0;
1851 /* unsetenv was already done */
1852 } else {
1853 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1854 return putenv(cur->varstr);
1855 }
1856 }
1857 return 0;
1858}
1859
1860/* Used at startup and after each cd */
1861static void set_pwd_var(int exp)
1862{
1863 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1864 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1865}
1866
1867static int unset_local_var_len(const char *name, int name_len)
1868{
1869 struct variable *cur;
1870 struct variable **var_pp;
1871
1872 if (!name)
1873 return EXIT_SUCCESS;
1874 var_pp = &G.top_var;
1875 while ((cur = *var_pp) != NULL) {
1876 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1877 if (cur->flg_read_only) {
1878 bb_error_msg("%s: readonly variable", name);
1879 return EXIT_FAILURE;
1880 }
1881 *var_pp = cur->next;
1882 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1883 bb_unsetenv(cur->varstr);
1884 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1885 cmdedit_update_prompt();
1886 if (!cur->max_len)
1887 free(cur->varstr);
1888 free(cur);
1889 return EXIT_SUCCESS;
1890 }
1891 var_pp = &cur->next;
1892 }
1893 return EXIT_SUCCESS;
1894}
1895
1896static int unset_local_var(const char *name)
1897{
1898 return unset_local_var_len(name, strlen(name));
1899}
1900
1901static void unset_vars(char **strings)
1902{
1903 char **v;
1904
1905 if (!strings)
1906 return;
1907 v = strings;
1908 while (*v) {
1909 const char *eq = strchrnul(*v, '=');
1910 unset_local_var_len(*v, (int)(eq - *v));
1911 v++;
1912 }
1913 free(strings);
1914}
1915
1916static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1917{
1918 char *var = xasprintf("%s=%s", name, val);
1919 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1920}
1921
1922
1923/*
1924 * Helpers for "var1=val1 var2=val2 cmd" feature
1925 */
1926static void add_vars(struct variable *var)
1927{
1928 struct variable *next;
1929
1930 while (var) {
1931 next = var->next;
1932 var->next = G.top_var;
1933 G.top_var = var;
1934 if (var->flg_export) {
1935 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1936 putenv(var->varstr);
1937 } else {
1938 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1939 }
1940 var = next;
1941 }
1942}
1943
1944static struct variable *set_vars_and_save_old(char **strings)
1945{
1946 char **s;
1947 struct variable *old = NULL;
1948
1949 if (!strings)
1950 return old;
1951 s = strings;
1952 while (*s) {
1953 struct variable *var_p;
1954 struct variable **var_pp;
1955 char *eq;
1956
1957 eq = strchr(*s, '=');
1958 if (eq) {
1959 var_pp = get_ptr_to_local_var(*s, eq - *s);
1960 if (var_pp) {
1961 /* Remove variable from global linked list */
1962 var_p = *var_pp;
1963 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1964 *var_pp = var_p->next;
1965 /* Add it to returned list */
1966 var_p->next = old;
1967 old = var_p;
1968 }
1969 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1970 }
1971 s++;
1972 }
1973 return old;
1974}
1975
1976
1977/*
1978 * in_str support
1979 */
1980static int FAST_FUNC static_get(struct in_str *i)
1981{
1982 int ch = *i->p;
1983 if (ch != '\0') {
1984 i->p++;
1985 i->last_char = ch;
1986 return ch;
1987 }
1988 return EOF;
1989}
1990
1991static int FAST_FUNC static_peek(struct in_str *i)
1992{
1993 return *i->p;
1994}
1995
1996#if ENABLE_HUSH_INTERACTIVE
1997
1998static void cmdedit_update_prompt(void)
1999{
2000 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2001 G.PS1 = get_local_var_value("PS1");
2002 if (G.PS1 == NULL)
2003 G.PS1 = "\\w \\$ ";
2004 G.PS2 = get_local_var_value("PS2");
2005 } else {
2006 G.PS1 = NULL;
2007 }
2008 if (G.PS2 == NULL)
2009 G.PS2 = "> ";
2010}
2011
2012static const char *setup_prompt_string(int promptmode)
2013{
2014 const char *prompt_str;
2015 debug_printf("setup_prompt_string %d ", promptmode);
2016 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2017 /* Set up the prompt */
2018 if (promptmode == 0) { /* PS1 */
2019 free((char*)G.PS1);
2020 /* bash uses $PWD value, even if it is set by user.
2021 * It uses current dir only if PWD is unset.
2022 * We always use current dir. */
2023 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2024 prompt_str = G.PS1;
2025 } else
2026 prompt_str = G.PS2;
2027 } else
2028 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2029 debug_printf("result '%s'\n", prompt_str);
2030 return prompt_str;
2031}
2032
2033static void get_user_input(struct in_str *i)
2034{
2035 int r;
2036 const char *prompt_str;
2037
2038 prompt_str = setup_prompt_string(i->promptmode);
2039# if ENABLE_FEATURE_EDITING
2040 /* Enable command line editing only while a command line
2041 * is actually being read */
2042 do {
2043 /* Unicode support should be activated even if LANG is set
2044 * _during_ shell execution, not only if it was set when
2045 * shell was started. Therefore, re-check LANG every time:
2046 */
2047 const char *s = get_local_var_value("LC_ALL");
2048 if (!s) s = get_local_var_value("LC_CTYPE");
2049 if (!s) s = get_local_var_value("LANG");
2050 reinit_unicode(s);
2051
2052 G.flag_SIGINT = 0;
2053 /* buglet: SIGINT will not make new prompt to appear _at once_,
2054 * only after <Enter>. (^C will work) */
2055 r = read_line_input(G.line_input_state, prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, /*timeout*/ -1);
2056 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2057 check_and_run_traps();
2058 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2059 i->eof_flag = (r < 0);
2060 if (i->eof_flag) { /* EOF/error detected */
2061 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
2062 G.user_input_buf[1] = '\0';
2063 }
2064# else
2065 do {
2066 G.flag_SIGINT = 0;
2067 if (i->last_char == '\0' || i->last_char == '\n') {
2068 /* Why check_and_run_traps here? Try this interactively:
2069 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2070 * $ <[enter], repeatedly...>
2071 * Without check_and_run_traps, handler never runs.
2072 */
2073 check_and_run_traps();
2074 fputs(prompt_str, stdout);
2075 }
2076 fflush_all();
2077 G.user_input_buf[0] = r = fgetc(i->file);
2078 /*G.user_input_buf[1] = '\0'; - already is and never changed */
2079 } while (G.flag_SIGINT);
2080 i->eof_flag = (r == EOF);
2081# endif
2082 i->p = G.user_input_buf;
2083}
2084
2085#endif /* INTERACTIVE */
2086
2087/* This is the magic location that prints prompts
2088 * and gets data back from the user */
2089static int FAST_FUNC file_get(struct in_str *i)
2090{
2091 int ch;
2092
2093 /* If there is data waiting, eat it up */
2094 if (i->p && *i->p) {
2095#if ENABLE_HUSH_INTERACTIVE
2096 take_cached:
2097#endif
2098 ch = *i->p++;
2099 if (i->eof_flag && !*i->p)
2100 ch = EOF;
2101 /* note: ch is never NUL */
2102 } else {
2103 /* need to double check i->file because we might be doing something
2104 * more complicated by now, like sourcing or substituting. */
2105#if ENABLE_HUSH_INTERACTIVE
2106 if (G_interactive_fd && i->file == stdin) {
2107 do {
2108 get_user_input(i);
2109 } while (!*i->p); /* need non-empty line */
2110 i->promptmode = 1; /* PS2 */
2111 goto take_cached;
2112 }
2113#endif
2114 do ch = fgetc(i->file); while (ch == '\0');
2115 }
2116 debug_printf("file_get: got '%c' %d\n", ch, ch);
2117 i->last_char = ch;
2118 return ch;
2119}
2120
2121/* All callers guarantee this routine will never
2122 * be used right after a newline, so prompting is not needed.
2123 */
2124static int FAST_FUNC file_peek(struct in_str *i)
2125{
2126 int ch;
2127 if (i->p && *i->p) {
2128 if (i->eof_flag && !i->p[1])
2129 return EOF;
2130 return *i->p;
2131 /* note: ch is never NUL */
2132 }
2133 do ch = fgetc(i->file); while (ch == '\0');
2134 i->eof_flag = (ch == EOF);
2135 i->peek_buf[0] = ch;
2136 i->peek_buf[1] = '\0';
2137 i->p = i->peek_buf;
2138 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2139 return ch;
2140}
2141
2142static void setup_file_in_str(struct in_str *i, FILE *f)
2143{
2144 memset(i, 0, sizeof(*i));
2145 i->peek = file_peek;
2146 i->get = file_get;
2147 /* i->promptmode = 0; - PS1 (memset did it) */
2148 i->file = f;
2149 /* i->p = NULL; */
2150}
2151
2152static void setup_string_in_str(struct in_str *i, const char *s)
2153{
2154 memset(i, 0, sizeof(*i));
2155 i->peek = static_peek;
2156 i->get = static_get;
2157 /* i->promptmode = 0; - PS1 (memset did it) */
2158 i->p = s;
2159 /* i->eof_flag = 0; */
2160}
2161
2162
2163/*
2164 * o_string support
2165 */
2166#define B_CHUNK (32 * sizeof(char*))
2167
2168static void o_reset_to_empty_unquoted(o_string *o)
2169{
2170 o->length = 0;
2171 o->has_quoted_part = 0;
2172 if (o->data)
2173 o->data[0] = '\0';
2174}
2175
2176static void o_free(o_string *o)
2177{
2178 free(o->data);
2179 memset(o, 0, sizeof(*o));
2180}
2181
2182static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2183{
2184 free(o->data);
2185}
2186
2187static void o_grow_by(o_string *o, int len)
2188{
2189 if (o->length + len > o->maxlen) {
2190 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2191 o->data = xrealloc(o->data, 1 + o->maxlen);
2192 }
2193}
2194
2195static void o_addchr(o_string *o, int ch)
2196{
2197 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2198 o_grow_by(o, 1);
2199 o->data[o->length] = ch;
2200 o->length++;
2201 o->data[o->length] = '\0';
2202}
2203
2204static void o_addblock(o_string *o, const char *str, int len)
2205{
2206 o_grow_by(o, len);
2207 memcpy(&o->data[o->length], str, len);
2208 o->length += len;
2209 o->data[o->length] = '\0';
2210}
2211
2212static void o_addstr(o_string *o, const char *str)
2213{
2214 o_addblock(o, str, strlen(str));
2215}
2216
2217#if !BB_MMU
2218static void nommu_addchr(o_string *o, int ch)
2219{
2220 if (o)
2221 o_addchr(o, ch);
2222}
2223#else
2224# define nommu_addchr(o, str) ((void)0)
2225#endif
2226
2227static void o_addstr_with_NUL(o_string *o, const char *str)
2228{
2229 o_addblock(o, str, strlen(str) + 1);
2230}
2231
2232/*
2233 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2234 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2235 * Apparently, on unquoted $v bash still does globbing
2236 * ("v='*.txt'; echo $v" prints all .txt files),
2237 * but NOT brace expansion! Thus, there should be TWO independent
2238 * quoting mechanisms on $v expansion side: one protects
2239 * $v from brace expansion, and other additionally protects "$v" against globbing.
2240 * We have only second one.
2241 */
2242
2243#if ENABLE_HUSH_BRACE_EXPANSION
2244# define MAYBE_BRACES "{}"
2245#else
2246# define MAYBE_BRACES ""
2247#endif
2248
2249/* My analysis of quoting semantics tells me that state information
2250 * is associated with a destination, not a source.
2251 */
2252static void o_addqchr(o_string *o, int ch)
2253{
2254 int sz = 1;
2255 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2256 if (found)
2257 sz++;
2258 o_grow_by(o, sz);
2259 if (found) {
2260 o->data[o->length] = '\\';
2261 o->length++;
2262 }
2263 o->data[o->length] = ch;
2264 o->length++;
2265 o->data[o->length] = '\0';
2266}
2267
2268static void o_addQchr(o_string *o, int ch)
2269{
2270 int sz = 1;
2271 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2272 && strchr("*?[\\" MAYBE_BRACES, ch)
2273 ) {
2274 sz++;
2275 o->data[o->length] = '\\';
2276 o->length++;
2277 }
2278 o_grow_by(o, sz);
2279 o->data[o->length] = ch;
2280 o->length++;
2281 o->data[o->length] = '\0';
2282}
2283
2284static void o_addqblock(o_string *o, const char *str, int len)
2285{
2286 while (len) {
2287 char ch;
2288 int sz;
2289 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2290 if (ordinary_cnt > len) /* paranoia */
2291 ordinary_cnt = len;
2292 o_addblock(o, str, ordinary_cnt);
2293 if (ordinary_cnt == len)
2294 return; /* NUL is already added by o_addblock */
2295 str += ordinary_cnt;
2296 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2297
2298 ch = *str++;
2299 sz = 1;
2300 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2301 sz++;
2302 o->data[o->length] = '\\';
2303 o->length++;
2304 }
2305 o_grow_by(o, sz);
2306 o->data[o->length] = ch;
2307 o->length++;
2308 }
2309 o->data[o->length] = '\0';
2310}
2311
2312static void o_addQblock(o_string *o, const char *str, int len)
2313{
2314 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2315 o_addblock(o, str, len);
2316 return;
2317 }
2318 o_addqblock(o, str, len);
2319}
2320
2321static void o_addQstr(o_string *o, const char *str)
2322{
2323 o_addQblock(o, str, strlen(str));
2324}
2325
2326/* A special kind of o_string for $VAR and `cmd` expansion.
2327 * It contains char* list[] at the beginning, which is grown in 16 element
2328 * increments. Actual string data starts at the next multiple of 16 * (char*).
2329 * list[i] contains an INDEX (int!) into this string data.
2330 * It means that if list[] needs to grow, data needs to be moved higher up
2331 * but list[i]'s need not be modified.
2332 * NB: remembering how many list[i]'s you have there is crucial.
2333 * o_finalize_list() operation post-processes this structure - calculates
2334 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2335 */
2336#if DEBUG_EXPAND || DEBUG_GLOB
2337static void debug_print_list(const char *prefix, o_string *o, int n)
2338{
2339 char **list = (char**)o->data;
2340 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2341 int i = 0;
2342
2343 indent();
2344 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2345 prefix, list, n, string_start, o->length, o->maxlen,
2346 !!(o->o_expflags & EXP_FLAG_GLOB),
2347 o->has_quoted_part,
2348 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2349 while (i < n) {
2350 indent();
2351 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2352 o->data + (int)(uintptr_t)list[i] + string_start,
2353 o->data + (int)(uintptr_t)list[i] + string_start);
2354 i++;
2355 }
2356 if (n) {
2357 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2358 indent();
2359 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2360 }
2361}
2362#else
2363# define debug_print_list(prefix, o, n) ((void)0)
2364#endif
2365
2366/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2367 * in list[n] so that it points past last stored byte so far.
2368 * It returns n+1. */
2369static int o_save_ptr_helper(o_string *o, int n)
2370{
2371 char **list = (char**)o->data;
2372 int string_start;
2373 int string_len;
2374
2375 if (!o->has_empty_slot) {
2376 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2377 string_len = o->length - string_start;
2378 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2379 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2380 /* list[n] points to string_start, make space for 16 more pointers */
2381 o->maxlen += 0x10 * sizeof(list[0]);
2382 o->data = xrealloc(o->data, o->maxlen + 1);
2383 list = (char**)o->data;
2384 memmove(list + n + 0x10, list + n, string_len);
2385 o->length += 0x10 * sizeof(list[0]);
2386 } else {
2387 debug_printf_list("list[%d]=%d string_start=%d\n",
2388 n, string_len, string_start);
2389 }
2390 } else {
2391 /* We have empty slot at list[n], reuse without growth */
2392 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2393 string_len = o->length - string_start;
2394 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2395 n, string_len, string_start);
2396 o->has_empty_slot = 0;
2397 }
2398 o->has_quoted_part = 0;
2399 list[n] = (char*)(uintptr_t)string_len;
2400 return n + 1;
2401}
2402
2403/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2404static int o_get_last_ptr(o_string *o, int n)
2405{
2406 char **list = (char**)o->data;
2407 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2408
2409 return ((int)(uintptr_t)list[n-1]) + string_start;
2410}
2411
2412#if ENABLE_HUSH_BRACE_EXPANSION
2413/* There in a GNU extension, GLOB_BRACE, but it is not usable:
2414 * first, it processes even {a} (no commas), second,
2415 * I didn't manage to make it return strings when they don't match
2416 * existing files. Need to re-implement it.
2417 */
2418
2419/* Helper */
2420static int glob_needed(const char *s)
2421{
2422 while (*s) {
2423 if (*s == '\\') {
2424 if (!s[1])
2425 return 0;
2426 s += 2;
2427 continue;
2428 }
2429 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2430 return 1;
2431 s++;
2432 }
2433 return 0;
2434}
2435/* Return pointer to next closing brace or to comma */
2436static const char *next_brace_sub(const char *cp)
2437{
2438 unsigned depth = 0;
2439 cp++;
2440 while (*cp != '\0') {
2441 if (*cp == '\\') {
2442 if (*++cp == '\0')
2443 break;
2444 cp++;
2445 continue;
2446 }
2447 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2448 break;
2449 if (*cp++ == '{')
2450 depth++;
2451 }
2452
2453 return *cp != '\0' ? cp : NULL;
2454}
2455/* Recursive brace globber. Note: may garble pattern[]. */
2456static int glob_brace(char *pattern, o_string *o, int n)
2457{
2458 char *new_pattern_buf;
2459 const char *begin;
2460 const char *next;
2461 const char *rest;
2462 const char *p;
2463 size_t rest_len;
2464
2465 debug_printf_glob("glob_brace('%s')\n", pattern);
2466
2467 begin = pattern;
2468 while (1) {
2469 if (*begin == '\0')
2470 goto simple_glob;
2471 if (*begin == '{') {
2472 /* Find the first sub-pattern and at the same time
2473 * find the rest after the closing brace */
2474 next = next_brace_sub(begin);
2475 if (next == NULL) {
2476 /* An illegal expression */
2477 goto simple_glob;
2478 }
2479 if (*next == '}') {
2480 /* "{abc}" with no commas - illegal
2481 * brace expr, disregard and skip it */
2482 begin = next + 1;
2483 continue;
2484 }
2485 break;
2486 }
2487 if (*begin == '\\' && begin[1] != '\0')
2488 begin++;
2489 begin++;
2490 }
2491 debug_printf_glob("begin:%s\n", begin);
2492 debug_printf_glob("next:%s\n", next);
2493
2494 /* Now find the end of the whole brace expression */
2495 rest = next;
2496 while (*rest != '}') {
2497 rest = next_brace_sub(rest);
2498 if (rest == NULL) {
2499 /* An illegal expression */
2500 goto simple_glob;
2501 }
2502 debug_printf_glob("rest:%s\n", rest);
2503 }
2504 rest_len = strlen(++rest) + 1;
2505
2506 /* We are sure the brace expression is well-formed */
2507
2508 /* Allocate working buffer large enough for our work */
2509 new_pattern_buf = xmalloc(strlen(pattern));
2510
2511 /* We have a brace expression. BEGIN points to the opening {,
2512 * NEXT points past the terminator of the first element, and REST
2513 * points past the final }. We will accumulate result names from
2514 * recursive runs for each brace alternative in the buffer using
2515 * GLOB_APPEND. */
2516
2517 p = begin + 1;
2518 while (1) {
2519 /* Construct the new glob expression */
2520 memcpy(
2521 mempcpy(
2522 mempcpy(new_pattern_buf,
2523 /* We know the prefix for all sub-patterns */
2524 pattern, begin - pattern),
2525 p, next - p),
2526 rest, rest_len);
2527
2528 /* Note: glob_brace() may garble new_pattern_buf[].
2529 * That's why we re-copy prefix every time (1st memcpy above).
2530 */
2531 n = glob_brace(new_pattern_buf, o, n);
2532 if (*next == '}') {
2533 /* We saw the last entry */
2534 break;
2535 }
2536 p = next + 1;
2537 next = next_brace_sub(next);
2538 }
2539 free(new_pattern_buf);
2540 return n;
2541
2542 simple_glob:
2543 {
2544 int gr;
2545 glob_t globdata;
2546
2547 memset(&globdata, 0, sizeof(globdata));
2548 gr = glob(pattern, 0, NULL, &globdata);
2549 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2550 if (gr != 0) {
2551 if (gr == GLOB_NOMATCH) {
2552 globfree(&globdata);
2553 /* NB: garbles parameter */
2554 unbackslash(pattern);
2555 o_addstr_with_NUL(o, pattern);
2556 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2557 return o_save_ptr_helper(o, n);
2558 }
2559 if (gr == GLOB_NOSPACE)
2560 bb_error_msg_and_die("%s", bb_msg_memory_exhausted);
2561 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2562 * but we didn't specify it. Paranoia again. */
2563 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2564 }
2565 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2566 char **argv = globdata.gl_pathv;
2567 while (1) {
2568 o_addstr_with_NUL(o, *argv);
2569 n = o_save_ptr_helper(o, n);
2570 argv++;
2571 if (!*argv)
2572 break;
2573 }
2574 }
2575 globfree(&globdata);
2576 }
2577 return n;
2578}
2579/* Performs globbing on last list[],
2580 * saving each result as a new list[].
2581 */
2582static int perform_glob(o_string *o, int n)
2583{
2584 char *pattern, *copy;
2585
2586 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2587 if (!o->data)
2588 return o_save_ptr_helper(o, n);
2589 pattern = o->data + o_get_last_ptr(o, n);
2590 debug_printf_glob("glob pattern '%s'\n", pattern);
2591 if (!glob_needed(pattern)) {
2592 /* unbackslash last string in o in place, fix length */
2593 o->length = unbackslash(pattern) - o->data;
2594 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2595 return o_save_ptr_helper(o, n);
2596 }
2597
2598 copy = xstrdup(pattern);
2599 /* "forget" pattern in o */
2600 o->length = pattern - o->data;
2601 n = glob_brace(copy, o, n);
2602 free(copy);
2603 if (DEBUG_GLOB)
2604 debug_print_list("perform_glob returning", o, n);
2605 return n;
2606}
2607
2608#else /* !HUSH_BRACE_EXPANSION */
2609
2610/* Helper */
2611static int glob_needed(const char *s)
2612{
2613 while (*s) {
2614 if (*s == '\\') {
2615 if (!s[1])
2616 return 0;
2617 s += 2;
2618 continue;
2619 }
2620 if (*s == '*' || *s == '[' || *s == '?')
2621 return 1;
2622 s++;
2623 }
2624 return 0;
2625}
2626/* Performs globbing on last list[],
2627 * saving each result as a new list[].
2628 */
2629static int perform_glob(o_string *o, int n)
2630{
2631 glob_t globdata;
2632 int gr;
2633 char *pattern;
2634
2635 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2636 if (!o->data)
2637 return o_save_ptr_helper(o, n);
2638 pattern = o->data + o_get_last_ptr(o, n);
2639 debug_printf_glob("glob pattern '%s'\n", pattern);
2640 if (!glob_needed(pattern)) {
2641 literal:
2642 /* unbackslash last string in o in place, fix length */
2643 o->length = unbackslash(pattern) - o->data;
2644 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2645 return o_save_ptr_helper(o, n);
2646 }
2647
2648 memset(&globdata, 0, sizeof(globdata));
2649 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2650 * If we glob "*.\*" and don't find anything, we need
2651 * to fall back to using literal "*.*", but GLOB_NOCHECK
2652 * will return "*.\*"!
2653 */
2654 gr = glob(pattern, 0, NULL, &globdata);
2655 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2656 if (gr != 0) {
2657 if (gr == GLOB_NOMATCH) {
2658 globfree(&globdata);
2659 goto literal;
2660 }
2661 if (gr == GLOB_NOSPACE)
2662 bb_error_msg_and_die("%s", bb_msg_memory_exhausted);
2663 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2664 * but we didn't specify it. Paranoia again. */
2665 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2666 }
2667 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2668 char **argv = globdata.gl_pathv;
2669 /* "forget" pattern in o */
2670 o->length = pattern - o->data;
2671 while (1) {
2672 o_addstr_with_NUL(o, *argv);
2673 n = o_save_ptr_helper(o, n);
2674 argv++;
2675 if (!*argv)
2676 break;
2677 }
2678 }
2679 globfree(&globdata);
2680 if (DEBUG_GLOB)
2681 debug_print_list("perform_glob returning", o, n);
2682 return n;
2683}
2684
2685#endif /* !HUSH_BRACE_EXPANSION */
2686
2687/* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2688 * Otherwise, just finish current list[] and start new */
2689static int o_save_ptr(o_string *o, int n)
2690{
2691 if (o->o_expflags & EXP_FLAG_GLOB) {
2692 /* If o->has_empty_slot, list[n] was already globbed
2693 * (if it was requested back then when it was filled)
2694 * so don't do that again! */
2695 if (!o->has_empty_slot)
2696 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2697 }
2698 return o_save_ptr_helper(o, n);
2699}
2700
2701/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2702static char **o_finalize_list(o_string *o, int n)
2703{
2704 char **list;
2705 int string_start;
2706
2707 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2708 if (DEBUG_EXPAND)
2709 debug_print_list("finalized", o, n);
2710 debug_printf_expand("finalized n:%d\n", n);
2711 list = (char**)o->data;
2712 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2713 list[--n] = NULL;
2714 while (n) {
2715 n--;
2716 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2717 }
2718 return list;
2719}
2720
2721static void free_pipe_list(struct pipe *pi);
2722
2723/* Returns pi->next - next pipe in the list */
2724static struct pipe *free_pipe(struct pipe *pi)
2725{
2726 struct pipe *next;
2727 int i;
2728
2729 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2730 for (i = 0; i < pi->num_cmds; i++) {
2731 struct command *command;
2732 struct redir_struct *r, *rnext;
2733
2734 command = &pi->cmds[i];
2735 debug_printf_clean(" command %d:\n", i);
2736 if (command->argv) {
2737 if (DEBUG_CLEAN) {
2738 int a;
2739 char **p;
2740 for (a = 0, p = command->argv; *p; a++, p++) {
2741 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2742 }
2743 }
2744 free_strings(command->argv);
2745 //command->argv = NULL;
2746 }
2747 /* not "else if": on syntax error, we may have both! */
2748 if (command->group) {
2749 debug_printf_clean(" begin group (cmd_type:%d)\n",
2750 command->cmd_type);
2751 free_pipe_list(command->group);
2752 debug_printf_clean(" end group\n");
2753 //command->group = NULL;
2754 }
2755 /* else is crucial here.
2756 * If group != NULL, child_func is meaningless */
2757#if ENABLE_HUSH_FUNCTIONS
2758 else if (command->child_func) {
2759 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2760 command->child_func->parent_cmd = NULL;
2761 }
2762#endif
2763#if !BB_MMU
2764 free(command->group_as_string);
2765 //command->group_as_string = NULL;
2766#endif
2767 for (r = command->redirects; r; r = rnext) {
2768 debug_printf_clean(" redirect %d%s",
2769 r->rd_fd, redir_table[r->rd_type].descrip);
2770 /* guard against the case >$FOO, where foo is unset or blank */
2771 if (r->rd_filename) {
2772 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2773 free(r->rd_filename);
2774 //r->rd_filename = NULL;
2775 }
2776 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2777 rnext = r->next;
2778 free(r);
2779 }
2780 //command->redirects = NULL;
2781 }
2782 free(pi->cmds); /* children are an array, they get freed all at once */
2783 //pi->cmds = NULL;
2784#if ENABLE_HUSH_JOB
2785 free(pi->cmdtext);
2786 //pi->cmdtext = NULL;
2787#endif
2788
2789 next = pi->next;
2790 free(pi);
2791 return next;
2792}
2793
2794static void free_pipe_list(struct pipe *pi)
2795{
2796 while (pi) {
2797#if HAS_KEYWORDS
2798 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2799#endif
2800 debug_printf_clean("pipe followup code %d\n", pi->followup);
2801 pi = free_pipe(pi);
2802 }
2803}
2804
2805
2806/*** Parsing routines ***/
2807
2808#ifndef debug_print_tree
2809static void debug_print_tree(struct pipe *pi, int lvl)
2810{
2811 static const char *const PIPE[] = {
2812 [PIPE_SEQ] = "SEQ",
2813 [PIPE_AND] = "AND",
2814 [PIPE_OR ] = "OR" ,
2815 [PIPE_BG ] = "BG" ,
2816 };
2817 static const char *RES[] = {
2818 [RES_NONE ] = "NONE" ,
2819# if ENABLE_HUSH_IF
2820 [RES_IF ] = "IF" ,
2821 [RES_THEN ] = "THEN" ,
2822 [RES_ELIF ] = "ELIF" ,
2823 [RES_ELSE ] = "ELSE" ,
2824 [RES_FI ] = "FI" ,
2825# endif
2826# if ENABLE_HUSH_LOOPS
2827 [RES_FOR ] = "FOR" ,
2828 [RES_WHILE] = "WHILE",
2829 [RES_UNTIL] = "UNTIL",
2830 [RES_DO ] = "DO" ,
2831 [RES_DONE ] = "DONE" ,
2832# endif
2833# if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2834 [RES_IN ] = "IN" ,
2835# endif
2836# if ENABLE_HUSH_CASE
2837 [RES_CASE ] = "CASE" ,
2838 [RES_CASE_IN ] = "CASE_IN" ,
2839 [RES_MATCH] = "MATCH",
2840 [RES_CASE_BODY] = "CASE_BODY",
2841 [RES_ESAC ] = "ESAC" ,
2842# endif
2843 [RES_XXXX ] = "XXXX" ,
2844 [RES_SNTX ] = "SNTX" ,
2845 };
2846 static const char *const CMDTYPE[] = {
2847 "{}",
2848 "()",
2849 "[noglob]",
2850# if ENABLE_HUSH_FUNCTIONS
2851 "func()",
2852# endif
2853 };
2854
2855 int pin, prn;
2856
2857 pin = 0;
2858 while (pi) {
2859 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2860 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2861 prn = 0;
2862 while (prn < pi->num_cmds) {
2863 struct command *command = &pi->cmds[prn];
2864 char **argv = command->argv;
2865
2866 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
2867 lvl*2, "", prn,
2868 command->assignment_cnt);
2869 if (command->group) {
2870 fdprintf(2, " group %s: (argv=%p)%s%s\n",
2871 CMDTYPE[command->cmd_type],
2872 argv
2873# if !BB_MMU
2874 , " group_as_string:", command->group_as_string
2875# else
2876 , "", ""
2877# endif
2878 );
2879 debug_print_tree(command->group, lvl+1);
2880 prn++;
2881 continue;
2882 }
2883 if (argv) while (*argv) {
2884 fdprintf(2, " '%s'", *argv);
2885 argv++;
2886 }
2887 fdprintf(2, "\n");
2888 prn++;
2889 }
2890 pi = pi->next;
2891 pin++;
2892 }
2893}
2894#endif /* debug_print_tree */
2895
2896static struct pipe *new_pipe(void)
2897{
2898 struct pipe *pi;
2899 pi = xzalloc(sizeof(struct pipe));
2900 /*pi->followup = 0; - deliberately invalid value */
2901 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2902 return pi;
2903}
2904
2905/* Command (member of a pipe) is complete, or we start a new pipe
2906 * if ctx->command is NULL.
2907 * No errors possible here.
2908 */
2909static int done_command(struct parse_context *ctx)
2910{
2911 /* The command is really already in the pipe structure, so
2912 * advance the pipe counter and make a new, null command. */
2913 struct pipe *pi = ctx->pipe;
2914 struct command *command = ctx->command;
2915
2916 if (command) {
2917 if (IS_NULL_CMD(command)) {
2918 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2919 goto clear_and_ret;
2920 }
2921 pi->num_cmds++;
2922 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2923 //debug_print_tree(ctx->list_head, 20);
2924 } else {
2925 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2926 }
2927
2928 /* Only real trickiness here is that the uncommitted
2929 * command structure is not counted in pi->num_cmds. */
2930 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2931 ctx->command = command = &pi->cmds[pi->num_cmds];
2932 clear_and_ret:
2933 memset(command, 0, sizeof(*command));
2934 return pi->num_cmds; /* used only for 0/nonzero check */
2935}
2936
2937static void done_pipe(struct parse_context *ctx, pipe_style type)
2938{
2939 int not_null;
2940
2941 debug_printf_parse("done_pipe entered, followup %d\n", type);
2942 /* Close previous command */
2943 not_null = done_command(ctx);
2944 ctx->pipe->followup = type;
2945#if HAS_KEYWORDS
2946 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2947 ctx->ctx_inverted = 0;
2948 ctx->pipe->res_word = ctx->ctx_res_w;
2949#endif
2950
2951 /* Without this check, even just <enter> on command line generates
2952 * tree of three NOPs (!). Which is harmless but annoying.
2953 * IOW: it is safe to do it unconditionally. */
2954 if (not_null
2955#if ENABLE_HUSH_IF
2956 || ctx->ctx_res_w == RES_FI
2957#endif
2958#if ENABLE_HUSH_LOOPS
2959 || ctx->ctx_res_w == RES_DONE
2960 || ctx->ctx_res_w == RES_FOR
2961 || ctx->ctx_res_w == RES_IN
2962#endif
2963#if ENABLE_HUSH_CASE
2964 || ctx->ctx_res_w == RES_ESAC
2965#endif
2966 ) {
2967 struct pipe *new_p;
2968 debug_printf_parse("done_pipe: adding new pipe: "
2969 "not_null:%d ctx->ctx_res_w:%d\n",
2970 not_null, ctx->ctx_res_w);
2971 new_p = new_pipe();
2972 ctx->pipe->next = new_p;
2973 ctx->pipe = new_p;
2974 /* RES_THEN, RES_DO etc are "sticky" -
2975 * they remain set for pipes inside if/while.
2976 * This is used to control execution.
2977 * RES_FOR and RES_IN are NOT sticky (needed to support
2978 * cases where variable or value happens to match a keyword):
2979 */
2980#if ENABLE_HUSH_LOOPS
2981 if (ctx->ctx_res_w == RES_FOR
2982 || ctx->ctx_res_w == RES_IN)
2983 ctx->ctx_res_w = RES_NONE;
2984#endif
2985#if ENABLE_HUSH_CASE
2986 if (ctx->ctx_res_w == RES_MATCH)
2987 ctx->ctx_res_w = RES_CASE_BODY;
2988 if (ctx->ctx_res_w == RES_CASE)
2989 ctx->ctx_res_w = RES_CASE_IN;
2990#endif
2991 ctx->command = NULL; /* trick done_command below */
2992 /* Create the memory for command, roughly:
2993 * ctx->pipe->cmds = new struct command;
2994 * ctx->command = &ctx->pipe->cmds[0];
2995 */
2996 done_command(ctx);
2997 //debug_print_tree(ctx->list_head, 10);
2998 }
2999 debug_printf_parse("done_pipe return\n");
3000}
3001
3002static void initialize_context(struct parse_context *ctx)
3003{
3004 memset(ctx, 0, sizeof(*ctx));
3005 ctx->pipe = ctx->list_head = new_pipe();
3006 /* Create the memory for command, roughly:
3007 * ctx->pipe->cmds = new struct command;
3008 * ctx->command = &ctx->pipe->cmds[0];
3009 */
3010 done_command(ctx);
3011}
3012
3013/* If a reserved word is found and processed, parse context is modified
3014 * and 1 is returned.
3015 */
3016#if HAS_KEYWORDS
3017struct reserved_combo {
3018 char literal[6];
3019 unsigned char res;
3020 unsigned char assignment_flag;
3021 int flag;
3022};
3023enum {
3024 FLAG_END = (1 << RES_NONE ),
3025# if ENABLE_HUSH_IF
3026 FLAG_IF = (1 << RES_IF ),
3027 FLAG_THEN = (1 << RES_THEN ),
3028 FLAG_ELIF = (1 << RES_ELIF ),
3029 FLAG_ELSE = (1 << RES_ELSE ),
3030 FLAG_FI = (1 << RES_FI ),
3031# endif
3032# if ENABLE_HUSH_LOOPS
3033 FLAG_FOR = (1 << RES_FOR ),
3034 FLAG_WHILE = (1 << RES_WHILE),
3035 FLAG_UNTIL = (1 << RES_UNTIL),
3036 FLAG_DO = (1 << RES_DO ),
3037 FLAG_DONE = (1 << RES_DONE ),
3038 FLAG_IN = (1 << RES_IN ),
3039# endif
3040# if ENABLE_HUSH_CASE
3041 FLAG_MATCH = (1 << RES_MATCH),
3042 FLAG_ESAC = (1 << RES_ESAC ),
3043# endif
3044 FLAG_START = (1 << RES_XXXX ),
3045};
3046
3047static const struct reserved_combo* match_reserved_word(o_string *word)
3048{
3049 /* Mostly a list of accepted follow-up reserved words.
3050 * FLAG_END means we are done with the sequence, and are ready
3051 * to turn the compound list into a command.
3052 * FLAG_START means the word must start a new compound list.
3053 */
3054 static const struct reserved_combo reserved_list[] = {
3055# if ENABLE_HUSH_IF
3056 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3057 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3058 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3059 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3060 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3061 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3062# endif
3063# if ENABLE_HUSH_LOOPS
3064 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3065 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3066 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3067 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3068 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3069 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3070# endif
3071# if ENABLE_HUSH_CASE
3072 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3073 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3074# endif
3075 };
3076 const struct reserved_combo *r;
3077
3078 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3079 if (strcmp(word->data, r->literal) == 0)
3080 return r;
3081 }
3082 return NULL;
3083}
3084/* Return 0: not a keyword, 1: keyword
3085 */
3086static int reserved_word(o_string *word, struct parse_context *ctx)
3087{
3088# if ENABLE_HUSH_CASE
3089 static const struct reserved_combo reserved_match = {
3090 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3091 };
3092# endif
3093 const struct reserved_combo *r;
3094
3095 if (word->has_quoted_part)
3096 return 0;
3097 r = match_reserved_word(word);
3098 if (!r)
3099 return 0;
3100
3101 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3102# if ENABLE_HUSH_CASE
3103 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3104 /* "case word IN ..." - IN part starts first MATCH part */
3105 r = &reserved_match;
3106 } else
3107# endif
3108 if (r->flag == 0) { /* '!' */
3109 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3110 syntax_error("! ! command");
3111 ctx->ctx_res_w = RES_SNTX;
3112 }
3113 ctx->ctx_inverted = 1;
3114 return 1;
3115 }
3116 if (r->flag & FLAG_START) {
3117 struct parse_context *old;
3118
3119 old = xmalloc(sizeof(*old));
3120 debug_printf_parse("push stack %p\n", old);
3121 *old = *ctx; /* physical copy */
3122 initialize_context(ctx);
3123 ctx->stack = old;
3124 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3125 syntax_error_at(word->data);
3126 ctx->ctx_res_w = RES_SNTX;
3127 return 1;
3128 } else {
3129 /* "{...} fi" is ok. "{...} if" is not
3130 * Example:
3131 * if { echo foo; } then { echo bar; } fi */
3132 if (ctx->command->group)
3133 done_pipe(ctx, PIPE_SEQ);
3134 }
3135
3136 ctx->ctx_res_w = r->res;
3137 ctx->old_flag = r->flag;
3138 word->o_assignment = r->assignment_flag;
3139 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3140
3141 if (ctx->old_flag & FLAG_END) {
3142 struct parse_context *old;
3143
3144 done_pipe(ctx, PIPE_SEQ);
3145 debug_printf_parse("pop stack %p\n", ctx->stack);
3146 old = ctx->stack;
3147 old->command->group = ctx->list_head;
3148 old->command->cmd_type = CMD_NORMAL;
3149# if !BB_MMU
3150 o_addstr(&old->as_string, ctx->as_string.data);
3151 o_free_unsafe(&ctx->as_string);
3152 old->command->group_as_string = xstrdup(old->as_string.data);
3153 debug_printf_parse("pop, remembering as:'%s'\n",
3154 old->command->group_as_string);
3155# endif
3156 *ctx = *old; /* physical copy */
3157 free(old);
3158 }
3159 return 1;
3160}
3161#endif /* HAS_KEYWORDS */
3162
3163/* Word is complete, look at it and update parsing context.
3164 * Normal return is 0. Syntax errors return 1.
3165 * Note: on return, word is reset, but not o_free'd!
3166 */
3167static int done_word(o_string *word, struct parse_context *ctx)
3168{
3169 struct command *command = ctx->command;
3170
3171 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3172 if (word->length == 0 && !word->has_quoted_part) {
3173 debug_printf_parse("done_word return 0: true null, ignored\n");
3174 return 0;
3175 }
3176
3177 if (ctx->pending_redirect) {
3178 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3179 * only if run as "bash", not "sh" */
3180 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3181 * "2.7 Redirection
3182 * ...the word that follows the redirection operator
3183 * shall be subjected to tilde expansion, parameter expansion,
3184 * command substitution, arithmetic expansion, and quote
3185 * removal. Pathname expansion shall not be performed
3186 * on the word by a non-interactive shell; an interactive
3187 * shell may perform it, but shall do so only when
3188 * the expansion would result in one word."
3189 */
3190 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3191 /* Cater for >\file case:
3192 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3193 * Same with heredocs:
3194 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3195 */
3196 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3197 unbackslash(ctx->pending_redirect->rd_filename);
3198 /* Is it <<"HEREDOC"? */
3199 if (word->has_quoted_part) {
3200 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3201 }
3202 }
3203 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3204 ctx->pending_redirect = NULL;
3205 } else {
3206#if HAS_KEYWORDS
3207# if ENABLE_HUSH_CASE
3208 if (ctx->ctx_dsemicolon
3209 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3210 ) {
3211 /* already done when ctx_dsemicolon was set to 1: */
3212 /* ctx->ctx_res_w = RES_MATCH; */
3213 ctx->ctx_dsemicolon = 0;
3214 } else
3215# endif
3216 if (!command->argv /* if it's the first word... */
3217# if ENABLE_HUSH_LOOPS
3218 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3219 && ctx->ctx_res_w != RES_IN
3220# endif
3221# if ENABLE_HUSH_CASE
3222 && ctx->ctx_res_w != RES_CASE
3223# endif
3224 ) {
3225 int reserved = reserved_word(word, ctx);
3226 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3227 if (reserved) {
3228 o_reset_to_empty_unquoted(word);
3229 debug_printf_parse("done_word return %d\n",
3230 (ctx->ctx_res_w == RES_SNTX));
3231 return (ctx->ctx_res_w == RES_SNTX);
3232 }
3233# if ENABLE_HUSH_BASH_COMPAT
3234 if (strcmp(word->data, "[[") == 0) {
3235 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3236 }
3237 /* fall through */
3238# endif
3239 }
3240#endif
3241 if (command->group) {
3242 /* "{ echo foo; } echo bar" - bad */
3243 syntax_error_at(word->data);
3244 debug_printf_parse("done_word return 1: syntax error, "
3245 "groups and arglists don't mix\n");
3246 return 1;
3247 }
3248
3249 /* If this word wasn't an assignment, next ones definitely
3250 * can't be assignments. Even if they look like ones. */
3251 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3252 && word->o_assignment != WORD_IS_KEYWORD
3253 ) {
3254 word->o_assignment = NOT_ASSIGNMENT;
3255 } else {
3256 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3257 command->assignment_cnt++;
3258 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3259 }
3260 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3261 word->o_assignment = MAYBE_ASSIGNMENT;
3262 }
3263 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3264
3265 if (word->has_quoted_part
3266 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3267 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3268 /* (otherwise it's known to be not empty and is already safe) */
3269 ) {
3270 /* exclude "$@" - it can expand to no word despite "" */
3271 char *p = word->data;
3272 while (p[0] == SPECIAL_VAR_SYMBOL
3273 && (p[1] & 0x7f) == '@'
3274 && p[2] == SPECIAL_VAR_SYMBOL
3275 ) {
3276 p += 3;
3277 }
3278 }
3279 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3280 debug_print_strings("word appended to argv", command->argv);
3281 }
3282
3283#if ENABLE_HUSH_LOOPS
3284 if (ctx->ctx_res_w == RES_FOR) {
3285 if (word->has_quoted_part
3286 || !is_well_formed_var_name(command->argv[0], '\0')
3287 ) {
3288 /* bash says just "not a valid identifier" */
3289 syntax_error("not a valid identifier in for");
3290 return 1;
3291 }
3292 /* Force FOR to have just one word (variable name) */
3293 /* NB: basically, this makes hush see "for v in ..."
3294 * syntax as if it is "for v; in ...". FOR and IN become
3295 * two pipe structs in parse tree. */
3296 done_pipe(ctx, PIPE_SEQ);
3297 }
3298#endif
3299#if ENABLE_HUSH_CASE
3300 /* Force CASE to have just one word */
3301 if (ctx->ctx_res_w == RES_CASE) {
3302 done_pipe(ctx, PIPE_SEQ);
3303 }
3304#endif
3305
3306 o_reset_to_empty_unquoted(word);
3307
3308 debug_printf_parse("done_word return 0\n");
3309 return 0;
3310}
3311
3312
3313/* Peek ahead in the input to find out if we have a "&n" construct,
3314 * as in "2>&1", that represents duplicating a file descriptor.
3315 * Return:
3316 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3317 * REDIRFD_SYNTAX_ERR if syntax error,
3318 * REDIRFD_TO_FILE if no & was seen,
3319 * or the number found.
3320 */
3321#if BB_MMU
3322#define parse_redir_right_fd(as_string, input) \
3323 parse_redir_right_fd(input)
3324#endif
3325static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3326{
3327 int ch, d, ok;
3328
3329 ch = i_peek(input);
3330 if (ch != '&')
3331 return REDIRFD_TO_FILE;
3332
3333 ch = i_getch(input); /* get the & */
3334 nommu_addchr(as_string, ch);
3335 ch = i_peek(input);
3336 if (ch == '-') {
3337 ch = i_getch(input);
3338 nommu_addchr(as_string, ch);
3339 return REDIRFD_CLOSE;
3340 }
3341 d = 0;
3342 ok = 0;
3343 while (ch != EOF && isdigit(ch)) {
3344 d = d*10 + (ch-'0');
3345 ok = 1;
3346 ch = i_getch(input);
3347 nommu_addchr(as_string, ch);
3348 ch = i_peek(input);
3349 }
3350 if (ok) return d;
3351
3352//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3353
3354 bb_error_msg("ambiguous redirect");
3355 return REDIRFD_SYNTAX_ERR;
3356}
3357
3358/* Return code is 0 normal, 1 if a syntax error is detected
3359 */
3360static int parse_redirect(struct parse_context *ctx,
3361 int fd,
3362 redir_type style,
3363 struct in_str *input)
3364{
3365 struct command *command = ctx->command;
3366 struct redir_struct *redir;
3367 struct redir_struct **redirp;
3368 int dup_num;
3369
3370 dup_num = REDIRFD_TO_FILE;
3371 if (style != REDIRECT_HEREDOC) {
3372 /* Check for a '>&1' type redirect */
3373 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3374 if (dup_num == REDIRFD_SYNTAX_ERR)
3375 return 1;
3376 } else {
3377 int ch = i_peek(input);
3378 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3379 if (dup_num) { /* <<-... */
3380 ch = i_getch(input);
3381 nommu_addchr(&ctx->as_string, ch);
3382 ch = i_peek(input);
3383 }
3384 }
3385
3386 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3387 int ch = i_peek(input);
3388 if (ch == '|') {
3389 /* >|FILE redirect ("clobbering" >).
3390 * Since we do not support "set -o noclobber" yet,
3391 * >| and > are the same for now. Just eat |.
3392 */
3393 ch = i_getch(input);
3394 nommu_addchr(&ctx->as_string, ch);
3395 }
3396 }
3397
3398 /* Create a new redir_struct and append it to the linked list */
3399 redirp = &command->redirects;
3400 while ((redir = *redirp) != NULL) {
3401 redirp = &(redir->next);
3402 }
3403 *redirp = redir = xzalloc(sizeof(*redir));
3404 /* redir->next = NULL; */
3405 /* redir->rd_filename = NULL; */
3406 redir->rd_type = style;
3407 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3408
3409 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3410 redir_table[style].descrip);
3411
3412 redir->rd_dup = dup_num;
3413 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3414 /* Erik had a check here that the file descriptor in question
3415 * is legit; I postpone that to "run time"
3416 * A "-" representation of "close me" shows up as a -3 here */
3417 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3418 redir->rd_fd, redir->rd_dup);
3419 } else {
3420 /* Set ctx->pending_redirect, so we know what to do at the
3421 * end of the next parsed word. */
3422 ctx->pending_redirect = redir;
3423 }
3424 return 0;
3425}
3426
3427/* If a redirect is immediately preceded by a number, that number is
3428 * supposed to tell which file descriptor to redirect. This routine
3429 * looks for such preceding numbers. In an ideal world this routine
3430 * needs to handle all the following classes of redirects...
3431 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3432 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3433 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3434 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3435 *
3436 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3437 * "2.7 Redirection
3438 * ... If n is quoted, the number shall not be recognized as part of
3439 * the redirection expression. For example:
3440 * echo \2>a
3441 * writes the character 2 into file a"
3442 * We are getting it right by setting ->has_quoted_part on any \<char>
3443 *
3444 * A -1 return means no valid number was found,
3445 * the caller should use the appropriate default for this redirection.
3446 */
3447static int redirect_opt_num(o_string *o)
3448{
3449 int num;
3450
3451 if (o->data == NULL)
3452 return -1;
3453 num = bb_strtou(o->data, NULL, 10);
3454 if (errno || num < 0)
3455 return -1;
3456 o_reset_to_empty_unquoted(o);
3457 return num;
3458}
3459
3460#if BB_MMU
3461#define fetch_till_str(as_string, input, word, skip_tabs) \
3462 fetch_till_str(input, word, skip_tabs)
3463#endif
3464static char *fetch_till_str(o_string *as_string,
3465 struct in_str *input,
3466 const char *word,
3467 int heredoc_flags)
3468{
3469 o_string heredoc = NULL_O_STRING;
3470 unsigned past_EOL;
3471 int prev = 0; /* not \ */
3472 int ch;
3473
3474 goto jump_in;
3475
3476 while (1) {
3477 ch = i_getch(input);
3478 if (ch != EOF)
3479 nommu_addchr(as_string, ch);
3480 if ((ch == '\n' || ch == EOF)
3481 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3482 ) {
3483 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3484 heredoc.data[past_EOL] = '\0';
3485 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3486 return heredoc.data;
3487 }
3488 while (ch == '\n') {
3489 o_addchr(&heredoc, ch);
3490 prev = ch;
3491 jump_in:
3492 past_EOL = heredoc.length;
3493 do {
3494 ch = i_getch(input);
3495 if (ch != EOF)
3496 nommu_addchr(as_string, ch);
3497 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3498 }
3499 }
3500 if (ch == EOF) {
3501 o_free_unsafe(&heredoc);
3502 return NULL;
3503 }
3504 o_addchr(&heredoc, ch);
3505 nommu_addchr(as_string, ch);
3506 if (prev == '\\' && ch == '\\')
3507 /* Correctly handle foo\\<eol> (not a line cont.) */
3508 prev = 0; /* not \ */
3509 else
3510 prev = ch;
3511 }
3512}
3513
3514/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3515 * and load them all. There should be exactly heredoc_cnt of them.
3516 */
3517static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3518{
3519 struct pipe *pi = ctx->list_head;
3520
3521 while (pi && heredoc_cnt) {
3522 int i;
3523 struct command *cmd = pi->cmds;
3524
3525 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3526 pi->num_cmds,
3527 cmd->argv ? cmd->argv[0] : "NONE");
3528 for (i = 0; i < pi->num_cmds; i++) {
3529 struct redir_struct *redir = cmd->redirects;
3530
3531 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3532 i, cmd->argv ? cmd->argv[0] : "NONE");
3533 while (redir) {
3534 if (redir->rd_type == REDIRECT_HEREDOC) {
3535 char *p;
3536
3537 redir->rd_type = REDIRECT_HEREDOC2;
3538 /* redir->rd_dup is (ab)used to indicate <<- */
3539 p = fetch_till_str(&ctx->as_string, input,
3540 redir->rd_filename, redir->rd_dup);
3541 if (!p) {
3542 syntax_error("unexpected EOF in here document");
3543 return 1;
3544 }
3545 free(redir->rd_filename);
3546 redir->rd_filename = p;
3547 heredoc_cnt--;
3548 }
3549 redir = redir->next;
3550 }
3551 cmd++;
3552 }
3553 pi = pi->next;
3554 }
3555#if 0
3556 /* Should be 0. If it isn't, it's a parse error */
3557 if (heredoc_cnt)
3558 bb_error_msg_and_die("heredoc BUG 2");
3559#endif
3560 return 0;
3561}
3562
3563
3564static int run_list(struct pipe *pi);
3565#if BB_MMU
3566#define parse_stream(pstring, input, end_trigger) \
3567 parse_stream(input, end_trigger)
3568#endif
3569static struct pipe *parse_stream(char **pstring,
3570 struct in_str *input,
3571 int end_trigger);
3572
3573
3574#if !ENABLE_HUSH_FUNCTIONS
3575#define parse_group(dest, ctx, input, ch) \
3576 parse_group(ctx, input, ch)
3577#endif
3578static int parse_group(o_string *dest, struct parse_context *ctx,
3579 struct in_str *input, int ch)
3580{
3581 /* dest contains characters seen prior to ( or {.
3582 * Typically it's empty, but for function defs,
3583 * it contains function name (without '()'). */
3584 struct pipe *pipe_list;
3585 int endch;
3586 struct command *command = ctx->command;
3587
3588 debug_printf_parse("parse_group entered\n");
3589#if ENABLE_HUSH_FUNCTIONS
3590 if (ch == '(' && !dest->has_quoted_part) {
3591 if (dest->length)
3592 if (done_word(dest, ctx))
3593 return 1;
3594 if (!command->argv)
3595 goto skip; /* (... */
3596 if (command->argv[1]) { /* word word ... (... */
3597 syntax_error_unexpected_ch('(');
3598 return 1;
3599 }
3600 /* it is "word(..." or "word (..." */
3601 do
3602 ch = i_getch(input);
3603 while (ch == ' ' || ch == '\t');
3604 if (ch != ')') {
3605 syntax_error_unexpected_ch(ch);
3606 return 1;
3607 }
3608 nommu_addchr(&ctx->as_string, ch);
3609 do
3610 ch = i_getch(input);
3611 while (ch == ' ' || ch == '\t' || ch == '\n');
3612 if (ch != '{') {
3613 syntax_error_unexpected_ch(ch);
3614 return 1;
3615 }
3616 nommu_addchr(&ctx->as_string, ch);
3617 command->cmd_type = CMD_FUNCDEF;
3618 goto skip;
3619 }
3620#endif
3621
3622#if 0 /* Prevented by caller */
3623 if (command->argv /* word [word]{... */
3624 || dest->length /* word{... */
3625 || dest->has_quoted_part /* ""{... */
3626 ) {
3627 syntax_error(NULL);
3628 debug_printf_parse("parse_group return 1: "
3629 "syntax error, groups and arglists don't mix\n");
3630 return 1;
3631 }
3632#endif
3633
3634#if ENABLE_HUSH_FUNCTIONS
3635 skip:
3636#endif
3637 endch = '}';
3638 if (ch == '(') {
3639 endch = ')';
3640 command->cmd_type = CMD_SUBSHELL;
3641 } else {
3642 /* bash does not allow "{echo...", requires whitespace */
3643 ch = i_getch(input);
3644 if (ch != ' ' && ch != '\t' && ch != '\n') {
3645 syntax_error_unexpected_ch(ch);
3646 return 1;
3647 }
3648 nommu_addchr(&ctx->as_string, ch);
3649 }
3650
3651 {
3652#if BB_MMU
3653# define as_string NULL
3654#else
3655 char *as_string = NULL;
3656#endif
3657 pipe_list = parse_stream(&as_string, input, endch);
3658#if !BB_MMU
3659 if (as_string)
3660 o_addstr(&ctx->as_string, as_string);
3661#endif
3662 /* empty ()/{} or parse error? */
3663 if (!pipe_list || pipe_list == ERR_PTR) {
3664 /* parse_stream already emitted error msg */
3665 if (!BB_MMU)
3666 free(as_string);
3667 debug_printf_parse("parse_group return 1: "
3668 "parse_stream returned %p\n", pipe_list);
3669 return 1;
3670 }
3671 command->group = pipe_list;
3672#if !BB_MMU
3673 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3674 command->group_as_string = as_string;
3675 debug_printf_parse("end of group, remembering as:'%s'\n",
3676 command->group_as_string);
3677#endif
3678#undef as_string
3679 }
3680 debug_printf_parse("parse_group return 0\n");
3681 return 0;
3682 /* command remains "open", available for possible redirects */
3683}
3684
3685#if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3686/* Subroutines for copying $(...) and `...` things */
3687static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3688/* '...' */
3689static int add_till_single_quote(o_string *dest, struct in_str *input)
3690{
3691 while (1) {
3692 int ch = i_getch(input);
3693 if (ch == EOF) {
3694 syntax_error_unterm_ch('\'');
3695 return 0;
3696 }
3697 if (ch == '\'')
3698 return 1;
3699 o_addchr(dest, ch);
3700 }
3701}
3702/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3703static int add_till_double_quote(o_string *dest, struct in_str *input)
3704{
3705 while (1) {
3706 int ch = i_getch(input);
3707 if (ch == EOF) {
3708 syntax_error_unterm_ch('"');
3709 return 0;
3710 }
3711 if (ch == '"')
3712 return 1;
3713 if (ch == '\\') { /* \x. Copy both chars. */
3714 o_addchr(dest, ch);
3715 ch = i_getch(input);
3716 }
3717 o_addchr(dest, ch);
3718 if (ch == '`') {
3719 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
3720 return 0;
3721 o_addchr(dest, ch);
3722 continue;
3723 }
3724 //if (ch == '$') ...
3725 }
3726}
3727/* Process `cmd` - copy contents until "`" is seen. Complicated by
3728 * \` quoting.
3729 * "Within the backquoted style of command substitution, backslash
3730 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3731 * The search for the matching backquote shall be satisfied by the first
3732 * backquote found without a preceding backslash; during this search,
3733 * if a non-escaped backquote is encountered within a shell comment,
3734 * a here-document, an embedded command substitution of the $(command)
3735 * form, or a quoted string, undefined results occur. A single-quoted
3736 * or double-quoted string that begins, but does not end, within the
3737 * "`...`" sequence produces undefined results."
3738 * Example Output
3739 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3740 */
3741static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3742{
3743 while (1) {
3744 int ch = i_getch(input);
3745 if (ch == '`')
3746 return 1;
3747 if (ch == '\\') {
3748 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3749 ch = i_getch(input);
3750 if (ch != '`'
3751 && ch != '$'
3752 && ch != '\\'
3753 && (!in_dquote || ch != '"')
3754 ) {
3755 o_addchr(dest, '\\');
3756 }
3757 }
3758 if (ch == EOF) {
3759 syntax_error_unterm_ch('`');
3760 return 0;
3761 }
3762 o_addchr(dest, ch);
3763 }
3764}
3765/* Process $(cmd) - copy contents until ")" is seen. Complicated by
3766 * quoting and nested ()s.
3767 * "With the $(command) style of command substitution, all characters
3768 * following the open parenthesis to the matching closing parenthesis
3769 * constitute the command. Any valid shell script can be used for command,
3770 * except a script consisting solely of redirections which produces
3771 * unspecified results."
3772 * Example Output
3773 * echo $(echo '(TEST)' BEST) (TEST) BEST
3774 * echo $(echo 'TEST)' BEST) TEST) BEST
3775 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3776 *
3777 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3778 * can contain arbitrary constructs, just like $(cmd).
3779 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3780 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3781 */
3782#define DOUBLE_CLOSE_CHAR_FLAG 0x80
3783static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3784{
3785 int ch;
3786 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3787# if ENABLE_HUSH_BASH_COMPAT
3788 char end_char2 = end_ch >> 8;
3789# endif
3790 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3791
3792 while (1) {
3793 ch = i_getch(input);
3794 if (ch == EOF) {
3795 syntax_error_unterm_ch(end_ch);
3796 return 0;
3797 }
3798 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3799 if (!dbl)
3800 break;
3801 /* we look for closing )) of $((EXPR)) */
3802 if (i_peek(input) == end_ch) {
3803 i_getch(input); /* eat second ')' */
3804 break;
3805 }
3806 }
3807 o_addchr(dest, ch);
3808 if (ch == '(' || ch == '{') {
3809 ch = (ch == '(' ? ')' : '}');
3810 if (!add_till_closing_bracket(dest, input, ch))
3811 return 0;
3812 o_addchr(dest, ch);
3813 continue;
3814 }
3815 if (ch == '\'') {
3816 if (!add_till_single_quote(dest, input))
3817 return 0;
3818 o_addchr(dest, ch);
3819 continue;
3820 }
3821 if (ch == '"') {
3822 if (!add_till_double_quote(dest, input))
3823 return 0;
3824 o_addchr(dest, ch);
3825 continue;
3826 }
3827 if (ch == '`') {
3828 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
3829 return 0;
3830 o_addchr(dest, ch);
3831 continue;
3832 }
3833 if (ch == '\\') {
3834 /* \x. Copy verbatim. Important for \(, \) */
3835 ch = i_getch(input);
3836 if (ch == EOF) {
3837 syntax_error_unterm_ch(')');
3838 return 0;
3839 }
3840 o_addchr(dest, ch);
3841 continue;
3842 }
3843 }
3844 return ch;
3845}
3846#endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3847
3848/* Return code: 0 for OK, 1 for syntax error */
3849#if BB_MMU
3850#define parse_dollar(as_string, dest, input, quote_mask) \
3851 parse_dollar(dest, input, quote_mask)
3852#define as_string NULL
3853#endif
3854static int parse_dollar(o_string *as_string,
3855 o_string *dest,
3856 struct in_str *input, unsigned char quote_mask)
3857{
3858 int ch = i_peek(input); /* first character after the $ */
3859
3860 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3861 if (isalpha(ch)) {
3862 ch = i_getch(input);
3863 nommu_addchr(as_string, ch);
3864 make_var:
3865 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3866 while (1) {
3867 debug_printf_parse(": '%c'\n", ch);
3868 o_addchr(dest, ch | quote_mask);
3869 quote_mask = 0;
3870 ch = i_peek(input);
3871 if (!isalnum(ch) && ch != '_')
3872 break;
3873 ch = i_getch(input);
3874 nommu_addchr(as_string, ch);
3875 }
3876 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3877 } else if (isdigit(ch)) {
3878 make_one_char_var:
3879 ch = i_getch(input);
3880 nommu_addchr(as_string, ch);
3881 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3882 debug_printf_parse(": '%c'\n", ch);
3883 o_addchr(dest, ch | quote_mask);
3884 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3885 } else switch (ch) {
3886 case '$': /* pid */
3887 case '!': /* last bg pid */
3888 case '?': /* last exit code */
3889 case '#': /* number of args */
3890 case '*': /* args */
3891 case '@': /* args */
3892 goto make_one_char_var;
3893 case '{': {
3894 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3895
3896 ch = i_getch(input); /* eat '{' */
3897 nommu_addchr(as_string, ch);
3898
3899 ch = i_getch(input); /* first char after '{' */
3900 /* It should be ${?}, or ${#var},
3901 * or even ${?+subst} - operator acting on a special variable,
3902 * or the beginning of variable name.
3903 */
3904 if (ch == EOF
3905 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3906 ) {
3907 bad_dollar_syntax:
3908 syntax_error_unterm_str("${name}");
3909 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
3910 return 0;
3911 }
3912 nommu_addchr(as_string, ch);
3913 ch |= quote_mask;
3914
3915 /* It's possible to just call add_till_closing_bracket() at this point.
3916 * However, this regresses some of our testsuite cases
3917 * which check invalid constructs like ${%}.
3918 * Oh well... let's check that the var name part is fine... */
3919
3920 while (1) {
3921 unsigned pos;
3922
3923 o_addchr(dest, ch);
3924 debug_printf_parse(": '%c'\n", ch);
3925
3926 ch = i_getch(input);
3927 nommu_addchr(as_string, ch);
3928 if (ch == '}')
3929 break;
3930
3931 if (!isalnum(ch) && ch != '_') {
3932 unsigned end_ch;
3933 unsigned char last_ch;
3934 /* handle parameter expansions
3935 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3936 */
3937 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3938 goto bad_dollar_syntax;
3939
3940 /* Eat everything until closing '}' (or ':') */
3941 end_ch = '}';
3942 if (ENABLE_HUSH_BASH_COMPAT
3943 && ch == ':'
3944 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3945 ) {
3946 /* It's ${var:N[:M]} thing */
3947 end_ch = '}' * 0x100 + ':';
3948 }
3949 if (ENABLE_HUSH_BASH_COMPAT
3950 && ch == '/'
3951 ) {
3952 /* It's ${var/[/]pattern[/repl]} thing */
3953 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3954 i_getch(input);
3955 nommu_addchr(as_string, '/');
3956 ch = '\\';
3957 }
3958 end_ch = '}' * 0x100 + '/';
3959 }
3960 o_addchr(dest, ch);
3961 again:
3962 if (!BB_MMU)
3963 pos = dest->length;
3964#if ENABLE_HUSH_DOLLAR_OPS
3965 last_ch = add_till_closing_bracket(dest, input, end_ch);
3966 if (last_ch == 0) /* error? */
3967 return 0;
3968#else
3969#error Simple code to only allow ${var} is not implemented
3970#endif
3971 if (as_string) {
3972 o_addstr(as_string, dest->data + pos);
3973 o_addchr(as_string, last_ch);
3974 }
3975
3976 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3977 /* close the first block: */
3978 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3979 /* while parsing N from ${var:N[:M]}
3980 * or pattern from ${var/[/]pattern[/repl]} */
3981 if ((end_ch & 0xff) == last_ch) {
3982 /* got ':' or '/'- parse the rest */
3983 end_ch = '}';
3984 goto again;
3985 }
3986 /* got '}' */
3987 if (end_ch == '}' * 0x100 + ':') {
3988 /* it's ${var:N} - emulate :999999999 */
3989 o_addstr(dest, "999999999");
3990 } /* else: it's ${var/[/]pattern} */
3991 }
3992 break;
3993 }
3994 }
3995 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3996 break;
3997 }
3998#if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3999 case '(': {
4000 unsigned pos;
4001
4002 ch = i_getch(input);
4003 nommu_addchr(as_string, ch);
4004# if ENABLE_SH_MATH_SUPPORT
4005 if (i_peek(input) == '(') {
4006 ch = i_getch(input);
4007 nommu_addchr(as_string, ch);
4008 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4009 o_addchr(dest, /*quote_mask |*/ '+');
4010 if (!BB_MMU)
4011 pos = dest->length;
4012 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4013 return 0; /* error */
4014 if (as_string) {
4015 o_addstr(as_string, dest->data + pos);
4016 o_addchr(as_string, ')');
4017 o_addchr(as_string, ')');
4018 }
4019 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4020 break;
4021 }
4022# endif
4023# if ENABLE_HUSH_TICK
4024 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4025 o_addchr(dest, quote_mask | '`');
4026 if (!BB_MMU)
4027 pos = dest->length;
4028 if (!add_till_closing_bracket(dest, input, ')'))
4029 return 0; /* error */
4030 if (as_string) {
4031 o_addstr(as_string, dest->data + pos);
4032 o_addchr(as_string, ')');
4033 }
4034 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4035# endif
4036 break;
4037 }
4038#endif
4039 case '_':
4040 ch = i_getch(input);
4041 nommu_addchr(as_string, ch);
4042 ch = i_peek(input);
4043 if (isalnum(ch)) { /* it's $_name or $_123 */
4044 ch = '_';
4045 goto make_var;
4046 }
4047 /* else: it's $_ */
4048 /* TODO: $_ and $-: */
4049 /* $_ Shell or shell script name; or last argument of last command
4050 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4051 * but in command's env, set to full pathname used to invoke it */
4052 /* $- Option flags set by set builtin or shell options (-i etc) */
4053 default:
4054 o_addQchr(dest, '$');
4055 }
4056 debug_printf_parse("parse_dollar return 1 (ok)\n");
4057 return 1;
4058#undef as_string
4059}
4060
4061#if BB_MMU
4062# if ENABLE_HUSH_BASH_COMPAT
4063#define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4064 encode_string(dest, input, dquote_end, process_bkslash)
4065# else
4066/* only ${var/pattern/repl} (its pattern part) needs additional mode */
4067#define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4068 encode_string(dest, input, dquote_end)
4069# endif
4070#define as_string NULL
4071
4072#else /* !MMU */
4073
4074# if ENABLE_HUSH_BASH_COMPAT
4075/* all parameters are needed, no macro tricks */
4076# else
4077#define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4078 encode_string(as_string, dest, input, dquote_end)
4079# endif
4080#endif
4081static int encode_string(o_string *as_string,
4082 o_string *dest,
4083 struct in_str *input,
4084 int dquote_end,
4085 int process_bkslash)
4086{
4087#if !ENABLE_HUSH_BASH_COMPAT
4088 const int process_bkslash = 1;
4089#endif
4090 int ch;
4091 int next;
4092
4093 again:
4094 ch = i_getch(input);
4095 if (ch != EOF)
4096 nommu_addchr(as_string, ch);
4097 if (ch == dquote_end) { /* may be only '"' or EOF */
4098 debug_printf_parse("encode_string return 1 (ok)\n");
4099 return 1;
4100 }
4101 /* note: can't move it above ch == dquote_end check! */
4102 if (ch == EOF) {
4103 syntax_error_unterm_ch('"');
4104 return 0; /* error */
4105 }
4106 next = '\0';
4107 if (ch != '\n') {
4108 next = i_peek(input);
4109 }
4110 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4111 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4112 if (process_bkslash && ch == '\\') {
4113 if (next == EOF) {
4114 syntax_error("\\<eof>");
4115 xfunc_die();
4116 }
4117 /* bash:
4118 * "The backslash retains its special meaning [in "..."]
4119 * only when followed by one of the following characters:
4120 * $, `, ", \, or <newline>. A double quote may be quoted
4121 * within double quotes by preceding it with a backslash."
4122 * NB: in (unquoted) heredoc, above does not apply to ",
4123 * therefore we check for it by "next == dquote_end" cond.
4124 */
4125 if (next == dquote_end || strchr("$`\\\n", next)) {
4126 ch = i_getch(input); /* eat next */
4127 if (ch == '\n')
4128 goto again; /* skip \<newline> */
4129 } /* else: ch remains == '\\', and we double it below: */
4130 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4131 nommu_addchr(as_string, ch);
4132 goto again;
4133 }
4134 if (ch == '$') {
4135 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4136 debug_printf_parse("encode_string return 0: "
4137 "parse_dollar returned 0 (error)\n");
4138 return 0;
4139 }
4140 goto again;
4141 }
4142#if ENABLE_HUSH_TICK
4143 if (ch == '`') {
4144 //unsigned pos = dest->length;
4145 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4146 o_addchr(dest, 0x80 | '`');
4147 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4148 return 0; /* error */
4149 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4150 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4151 goto again;
4152 }
4153#endif
4154 o_addQchr(dest, ch);
4155 goto again;
4156#undef as_string
4157}
4158
4159/*
4160 * Scan input until EOF or end_trigger char.
4161 * Return a list of pipes to execute, or NULL on EOF
4162 * or if end_trigger character is met.
4163 * On syntax error, exit if shell is not interactive,
4164 * reset parsing machinery and start parsing anew,
4165 * or return ERR_PTR.
4166 */
4167static struct pipe *parse_stream(char **pstring,
4168 struct in_str *input,
4169 int end_trigger)
4170{
4171 struct parse_context ctx;
4172 o_string dest = NULL_O_STRING;
4173 int heredoc_cnt;
4174
4175 /* Single-quote triggers a bypass of the main loop until its mate is
4176 * found. When recursing, quote state is passed in via dest->o_expflags.
4177 */
4178 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4179 end_trigger ? end_trigger : 'X');
4180 debug_enter();
4181
4182 /* If very first arg is "" or '', dest.data may end up NULL.
4183 * Preventing this: */
4184 o_addchr(&dest, '\0');
4185 dest.length = 0;
4186
4187 /* We used to separate words on $IFS here. This was wrong.
4188 * $IFS is used only for word splitting when $var is expanded,
4189 * here we should use blank chars as separators, not $IFS
4190 */
4191
4192 if (MAYBE_ASSIGNMENT != 0)
4193 dest.o_assignment = MAYBE_ASSIGNMENT;
4194 initialize_context(&ctx);
4195 heredoc_cnt = 0;
4196 while (1) {
4197 const char *is_blank;
4198 const char *is_special;
4199 int ch;
4200 int next;
4201 int redir_fd;
4202 redir_type redir_style;
4203
4204 ch = i_getch(input);
4205 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4206 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4207 if (ch == EOF) {
4208 struct pipe *pi;
4209
4210 if (heredoc_cnt) {
4211 syntax_error_unterm_str("here document");
4212 goto parse_error;
4213 }
4214 /* end_trigger == '}' case errors out earlier,
4215 * checking only ')' */
4216 if (end_trigger == ')') {
4217 syntax_error_unterm_ch('(');
4218 goto parse_error;
4219 }
4220
4221 if (done_word(&dest, &ctx)) {
4222 goto parse_error;
4223 }
4224 o_free(&dest);
4225 done_pipe(&ctx, PIPE_SEQ);
4226 pi = ctx.list_head;
4227 /* If we got nothing... */
4228 /* (this makes bare "&" cmd a no-op.
4229 * bash says: "syntax error near unexpected token '&'") */
4230 if (pi->num_cmds == 0
4231 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4232 ) {
4233 free_pipe_list(pi);
4234 pi = NULL;
4235 }
4236#if !BB_MMU
4237 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4238 if (pstring)
4239 *pstring = ctx.as_string.data;
4240 else
4241 o_free_unsafe(&ctx.as_string);
4242#endif
4243 debug_leave();
4244 debug_printf_parse("parse_stream return %p\n", pi);
4245 return pi;
4246 }
4247 nommu_addchr(&ctx.as_string, ch);
4248
4249 next = '\0';
4250 if (ch != '\n')
4251 next = i_peek(input);
4252
4253 is_special = "{}<>;&|()#'" /* special outside of "str" */
4254 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4255 /* Are { and } special here? */
4256 if (ctx.command->argv /* word [word]{... - non-special */
4257 || dest.length /* word{... - non-special */
4258 || dest.has_quoted_part /* ""{... - non-special */
4259 || (next != ';' /* }; - special */
4260 && next != ')' /* }) - special */
4261 && next != '&' /* }& and }&& ... - special */
4262 && next != '|' /* }|| ... - special */
4263 && !strchr(defifs, next) /* {word - non-special */
4264 )
4265 ) {
4266 /* They are not special, skip "{}" */
4267 is_special += 2;
4268 }
4269 is_special = strchr(is_special, ch);
4270 is_blank = strchr(defifs, ch);
4271
4272 if (!is_special && !is_blank) { /* ordinary char */
4273 ordinary_char:
4274 o_addQchr(&dest, ch);
4275 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4276 || dest.o_assignment == WORD_IS_KEYWORD)
4277 && ch == '='
4278 && is_well_formed_var_name(dest.data, '=')
4279 ) {
4280 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4281 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4282 }
4283 continue;
4284 }
4285
4286 if (is_blank) {
4287 if (done_word(&dest, &ctx)) {
4288 goto parse_error;
4289 }
4290 if (ch == '\n') {
4291 /* Is this a case when newline is simply ignored?
4292 * Some examples:
4293 * "cmd | <newline> cmd ..."
4294 * "case ... in <newline> word) ..."
4295 */
4296 if (IS_NULL_CMD(ctx.command)
4297 && dest.length == 0 && !dest.has_quoted_part
4298 ) {
4299 /* This newline can be ignored. But...
4300 * Without check #1, interactive shell
4301 * ignores even bare <newline>,
4302 * and shows the continuation prompt:
4303 * ps1_prompt$ <enter>
4304 * ps2> _ <=== wrong, should be ps1
4305 * Without check #2, "cmd & <newline>"
4306 * is similarly mistreated.
4307 * (BTW, this makes "cmd & cmd"
4308 * and "cmd && cmd" non-orthogonal.
4309 * Really, ask yourself, why
4310 * "cmd && <newline>" doesn't start
4311 * cmd but waits for more input?
4312 * No reason...)
4313 */
4314 struct pipe *pi = ctx.list_head;
4315 if (pi->num_cmds != 0 /* check #1 */
4316 && pi->followup != PIPE_BG /* check #2 */
4317 ) {
4318 continue;
4319 }
4320 }
4321 /* Treat newline as a command separator. */
4322 done_pipe(&ctx, PIPE_SEQ);
4323 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4324 if (heredoc_cnt) {
4325 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4326 goto parse_error;
4327 }
4328 heredoc_cnt = 0;
4329 }
4330 dest.o_assignment = MAYBE_ASSIGNMENT;
4331 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4332 ch = ';';
4333 /* note: if (is_blank) continue;
4334 * will still trigger for us */
4335 }
4336 }
4337
4338 /* "cmd}" or "cmd }..." without semicolon or &:
4339 * } is an ordinary char in this case, even inside { cmd; }
4340 * Pathological example: { ""}; } should exec "}" cmd
4341 */
4342 if (ch == '}') {
4343 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4344 || dest.length != 0 /* word} */
4345 || dest.has_quoted_part /* ""} */
4346 ) {
4347 goto ordinary_char;
4348 }
4349 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4350 goto skip_end_trigger;
4351 /* else: } does terminate a group */
4352 }
4353
4354 if (end_trigger && end_trigger == ch
4355 && (ch != ';' || heredoc_cnt == 0)
4356#if ENABLE_HUSH_CASE
4357 && (ch != ')'
4358 || ctx.ctx_res_w != RES_MATCH
4359 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4360 )
4361#endif
4362 ) {
4363 if (heredoc_cnt) {
4364 /* This is technically valid:
4365 * { cat <<HERE; }; echo Ok
4366 * heredoc
4367 * heredoc
4368 * HERE
4369 * but we don't support this.
4370 * We require heredoc to be in enclosing {}/(),
4371 * if any.
4372 */
4373 syntax_error_unterm_str("here document");
4374 goto parse_error;
4375 }
4376 if (done_word(&dest, &ctx)) {
4377 goto parse_error;
4378 }
4379 done_pipe(&ctx, PIPE_SEQ);
4380 dest.o_assignment = MAYBE_ASSIGNMENT;
4381 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4382 /* Do we sit outside of any if's, loops or case's? */
4383 if (!HAS_KEYWORDS
4384 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4385 ) {
4386 o_free(&dest);
4387#if !BB_MMU
4388 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4389 if (pstring)
4390 *pstring = ctx.as_string.data;
4391 else
4392 o_free_unsafe(&ctx.as_string);
4393#endif
4394 debug_leave();
4395 debug_printf_parse("parse_stream return %p: "
4396 "end_trigger char found\n",
4397 ctx.list_head);
4398 return ctx.list_head;
4399 }
4400 }
4401 skip_end_trigger:
4402 if (is_blank)
4403 continue;
4404
4405 /* Catch <, > before deciding whether this word is
4406 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4407 switch (ch) {
4408 case '>':
4409 redir_fd = redirect_opt_num(&dest);
4410 if (done_word(&dest, &ctx)) {
4411 goto parse_error;
4412 }
4413 redir_style = REDIRECT_OVERWRITE;
4414 if (next == '>') {
4415 redir_style = REDIRECT_APPEND;
4416 ch = i_getch(input);
4417 nommu_addchr(&ctx.as_string, ch);
4418 }
4419#if 0
4420 else if (next == '(') {
4421 syntax_error(">(process) not supported");
4422 goto parse_error;
4423 }
4424#endif
4425 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4426 goto parse_error;
4427 continue; /* back to top of while (1) */
4428 case '<':
4429 redir_fd = redirect_opt_num(&dest);
4430 if (done_word(&dest, &ctx)) {
4431 goto parse_error;
4432 }
4433 redir_style = REDIRECT_INPUT;
4434 if (next == '<') {
4435 redir_style = REDIRECT_HEREDOC;
4436 heredoc_cnt++;
4437 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4438 ch = i_getch(input);
4439 nommu_addchr(&ctx.as_string, ch);
4440 } else if (next == '>') {
4441 redir_style = REDIRECT_IO;
4442 ch = i_getch(input);
4443 nommu_addchr(&ctx.as_string, ch);
4444 }
4445#if 0
4446 else if (next == '(') {
4447 syntax_error("<(process) not supported");
4448 goto parse_error;
4449 }
4450#endif
4451 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4452 goto parse_error;
4453 continue; /* back to top of while (1) */
4454 case '#':
4455 if (dest.length == 0 && !dest.has_quoted_part) {
4456 /* skip "#comment" */
4457 while (1) {
4458 ch = i_peek(input);
4459 if (ch == EOF || ch == '\n')
4460 break;
4461 i_getch(input);
4462 /* note: we do not add it to &ctx.as_string */
4463 }
4464 nommu_addchr(&ctx.as_string, '\n');
4465 continue; /* back to top of while (1) */
4466 }
4467 break;
4468 case '\\':
4469 if (next == '\n') {
4470 /* It's "\<newline>" */
4471#if !BB_MMU
4472 /* Remove trailing '\' from ctx.as_string */
4473 ctx.as_string.data[--ctx.as_string.length] = '\0';
4474#endif
4475 ch = i_getch(input); /* eat it */
4476 continue; /* back to top of while (1) */
4477 }
4478 break;
4479 }
4480
4481 if (dest.o_assignment == MAYBE_ASSIGNMENT
4482 /* check that we are not in word in "a=1 2>word b=1": */
4483 && !ctx.pending_redirect
4484 ) {
4485 /* ch is a special char and thus this word
4486 * cannot be an assignment */
4487 dest.o_assignment = NOT_ASSIGNMENT;
4488 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4489 }
4490
4491 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4492
4493 switch (ch) {
4494 case '#': /* non-comment #: "echo a#b" etc */
4495 o_addQchr(&dest, ch);
4496 break;
4497 case '\\':
4498 if (next == EOF) {
4499 syntax_error("\\<eof>");
4500 xfunc_die();
4501 }
4502 ch = i_getch(input);
4503 /* note: ch != '\n' (that case does not reach this place) */
4504 o_addchr(&dest, '\\');
4505 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4506 o_addchr(&dest, ch);
4507 nommu_addchr(&ctx.as_string, ch);
4508 /* Example: echo Hello \2>file
4509 * we need to know that word 2 is quoted */
4510 dest.has_quoted_part = 1;
4511 break;
4512 case '$':
4513 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4514 debug_printf_parse("parse_stream parse error: "
4515 "parse_dollar returned 0 (error)\n");
4516 goto parse_error;
4517 }
4518 break;
4519 case '\'':
4520 dest.has_quoted_part = 1;
4521 if (next == '\'' && !ctx.pending_redirect) {
4522 insert_empty_quoted_str_marker:
4523 nommu_addchr(&ctx.as_string, next);
4524 i_getch(input); /* eat second ' */
4525 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4526 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4527 } else {
4528 while (1) {
4529 ch = i_getch(input);
4530 if (ch == EOF) {
4531 syntax_error_unterm_ch('\'');
4532 goto parse_error;
4533 }
4534 nommu_addchr(&ctx.as_string, ch);
4535 if (ch == '\'')
4536 break;
4537 o_addqchr(&dest, ch);
4538 }
4539 }
4540 break;
4541 case '"':
4542 dest.has_quoted_part = 1;
4543 if (next == '"' && !ctx.pending_redirect)
4544 goto insert_empty_quoted_str_marker;
4545 if (dest.o_assignment == NOT_ASSIGNMENT)
4546 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4547 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4548 goto parse_error;
4549 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4550 break;
4551#if ENABLE_HUSH_TICK
4552 case '`': {
4553 USE_FOR_NOMMU(unsigned pos;)
4554
4555 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4556 o_addchr(&dest, '`');
4557 USE_FOR_NOMMU(pos = dest.length;)
4558 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4559 goto parse_error;
4560# if !BB_MMU
4561 o_addstr(&ctx.as_string, dest.data + pos);
4562 o_addchr(&ctx.as_string, '`');
4563# endif
4564 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4565 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4566 break;
4567 }
4568#endif
4569 case ';':
4570#if ENABLE_HUSH_CASE
4571 case_semi:
4572#endif
4573 if (done_word(&dest, &ctx)) {
4574 goto parse_error;
4575 }
4576 done_pipe(&ctx, PIPE_SEQ);
4577#if ENABLE_HUSH_CASE
4578 /* Eat multiple semicolons, detect
4579 * whether it means something special */
4580 while (1) {
4581 ch = i_peek(input);
4582 if (ch != ';')
4583 break;
4584 ch = i_getch(input);
4585 nommu_addchr(&ctx.as_string, ch);
4586 if (ctx.ctx_res_w == RES_CASE_BODY) {
4587 ctx.ctx_dsemicolon = 1;
4588 ctx.ctx_res_w = RES_MATCH;
4589 break;
4590 }
4591 }
4592#endif
4593 new_cmd:
4594 /* We just finished a cmd. New one may start
4595 * with an assignment */
4596 dest.o_assignment = MAYBE_ASSIGNMENT;
4597 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4598 break;
4599 case '&':
4600 if (done_word(&dest, &ctx)) {
4601 goto parse_error;
4602 }
4603 if (next == '&') {
4604 ch = i_getch(input);
4605 nommu_addchr(&ctx.as_string, ch);
4606 done_pipe(&ctx, PIPE_AND);
4607 } else {
4608 done_pipe(&ctx, PIPE_BG);
4609 }
4610 goto new_cmd;
4611 case '|':
4612 if (done_word(&dest, &ctx)) {
4613 goto parse_error;
4614 }
4615#if ENABLE_HUSH_CASE
4616 if (ctx.ctx_res_w == RES_MATCH)
4617 break; /* we are in case's "word | word)" */
4618#endif
4619 if (next == '|') { /* || */
4620 ch = i_getch(input);
4621 nommu_addchr(&ctx.as_string, ch);
4622 done_pipe(&ctx, PIPE_OR);
4623 } else {
4624 /* we could pick up a file descriptor choice here
4625 * with redirect_opt_num(), but bash doesn't do it.
4626 * "echo foo 2| cat" yields "foo 2". */
4627 done_command(&ctx);
4628#if !BB_MMU
4629 o_reset_to_empty_unquoted(&ctx.as_string);
4630#endif
4631 }
4632 goto new_cmd;
4633 case '(':
4634#if ENABLE_HUSH_CASE
4635 /* "case... in [(]word)..." - skip '(' */
4636 if (ctx.ctx_res_w == RES_MATCH
4637 && ctx.command->argv == NULL /* not (word|(... */
4638 && dest.length == 0 /* not word(... */
4639 && dest.has_quoted_part == 0 /* not ""(... */
4640 ) {
4641 continue;
4642 }
4643#endif
4644 case '{':
4645 if (parse_group(&dest, &ctx, input, ch) != 0) {
4646 goto parse_error;
4647 }
4648 goto new_cmd;
4649 case ')':
4650#if ENABLE_HUSH_CASE
4651 if (ctx.ctx_res_w == RES_MATCH)
4652 goto case_semi;
4653#endif
4654 case '}':
4655 /* proper use of this character is caught by end_trigger:
4656 * if we see {, we call parse_group(..., end_trigger='}')
4657 * and it will match } earlier (not here). */
4658 syntax_error_unexpected_ch(ch);
4659 goto parse_error;
4660 default:
4661 if (HUSH_DEBUG)
4662 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4663 }
4664 } /* while (1) */
4665
4666 parse_error:
4667 {
4668 struct parse_context *pctx;
4669 IF_HAS_KEYWORDS(struct parse_context *p2;)
4670
4671 /* Clean up allocated tree.
4672 * Sample for finding leaks on syntax error recovery path.
4673 * Run it from interactive shell, watch pmap `pidof hush`.
4674 * while if false; then false; fi; do break; fi
4675 * Samples to catch leaks at execution:
4676 * while if (true | {true;}); then echo ok; fi; do break; done
4677 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4678 */
4679 pctx = &ctx;
4680 do {
4681 /* Update pipe/command counts,
4682 * otherwise freeing may miss some */
4683 done_pipe(pctx, PIPE_SEQ);
4684 debug_printf_clean("freeing list %p from ctx %p\n",
4685 pctx->list_head, pctx);
4686 debug_print_tree(pctx->list_head, 0);
4687 free_pipe_list(pctx->list_head);
4688 debug_printf_clean("freed list %p\n", pctx->list_head);
4689#if !BB_MMU
4690 o_free_unsafe(&pctx->as_string);
4691#endif
4692 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4693 if (pctx != &ctx) {
4694 free(pctx);
4695 }
4696 IF_HAS_KEYWORDS(pctx = p2;)
4697 } while (HAS_KEYWORDS && pctx);
4698
4699 o_free(&dest);
4700 G.last_exitcode = 1;
4701#if !BB_MMU
4702 if (pstring)
4703 *pstring = NULL;
4704#endif
4705 debug_leave();
4706 return ERR_PTR;
4707 }
4708}
4709
4710
4711/*** Execution routines ***/
4712
4713/* Expansion can recurse, need forward decls: */
4714#if !ENABLE_HUSH_BASH_COMPAT
4715/* only ${var/pattern/repl} (its pattern part) needs additional mode */
4716#define expand_string_to_string(str, do_unbackslash) \
4717 expand_string_to_string(str)
4718#endif
4719static char *expand_string_to_string(const char *str, int do_unbackslash);
4720#if ENABLE_HUSH_TICK
4721static int process_command_subs(o_string *dest, const char *s);
4722#endif
4723
4724/* expand_strvec_to_strvec() takes a list of strings, expands
4725 * all variable references within and returns a pointer to
4726 * a list of expanded strings, possibly with larger number
4727 * of strings. (Think VAR="a b"; echo $VAR).
4728 * This new list is allocated as a single malloc block.
4729 * NULL-terminated list of char* pointers is at the beginning of it,
4730 * followed by strings themselves.
4731 * Caller can deallocate entire list by single free(list). */
4732
4733/* A horde of its helpers come first: */
4734
4735static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4736{
4737 while (--len >= 0) {
4738 char c = *str++;
4739
4740#if ENABLE_HUSH_BRACE_EXPANSION
4741 if (c == '{' || c == '}') {
4742 /* { -> \{, } -> \} */
4743 o_addchr(o, '\\');
4744 /* And now we want to add { or } and continue:
4745 * o_addchr(o, c);
4746 * continue;
4747 * luckily, just falling throught achieves this.
4748 */
4749 }
4750#endif
4751 o_addchr(o, c);
4752 if (c == '\\') {
4753 /* \z -> \\\z; \<eol> -> \\<eol> */
4754 o_addchr(o, '\\');
4755 if (len) {
4756 len--;
4757 o_addchr(o, '\\');
4758 o_addchr(o, *str++);
4759 }
4760 }
4761 }
4762}
4763
4764/* Store given string, finalizing the word and starting new one whenever
4765 * we encounter IFS char(s). This is used for expanding variable values.
4766 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
4767 * Return in *ended_with_ifs:
4768 * 1 - ended with IFS char, else 0 (this includes case of empty str).
4769 */
4770static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
4771{
4772 int last_is_ifs = 0;
4773
4774 while (1) {
4775 int word_len;
4776
4777 if (!*str) /* EOL - do not finalize word */
4778 break;
4779 word_len = strcspn(str, G.ifs);
4780 if (word_len) {
4781 /* We have WORD_LEN leading non-IFS chars */
4782 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4783 o_addblock(output, str, word_len);
4784 } else {
4785 /* Protect backslashes against globbing up :)
4786 * Example: "v='\*'; echo b$v" prints "b\*"
4787 * (and does not try to glob on "*")
4788 */
4789 o_addblock_duplicate_backslash(output, str, word_len);
4790 /*/ Why can't we do it easier? */
4791 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4792 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4793 }
4794 last_is_ifs = 0;
4795 str += word_len;
4796 if (!*str) /* EOL - do not finalize word */
4797 break;
4798 }
4799
4800 /* We know str here points to at least one IFS char */
4801 last_is_ifs = 1;
4802 str += strspn(str, G.ifs); /* skip IFS chars */
4803 if (!*str) /* EOL - do not finalize word */
4804 break;
4805
4806 /* Start new word... but not always! */
4807 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
4808 if (output->has_quoted_part
4809 /* Case "v=' a'; echo $v":
4810 * here nothing precedes the space in $v expansion,
4811 * therefore we should not finish the word
4812 * (IOW: if there *is* word to finalize, only then do it):
4813 */
4814 || (n > 0 && output->data[output->length - 1])
4815 ) {
4816 o_addchr(output, '\0');
4817 debug_print_list("expand_on_ifs", output, n);
4818 n = o_save_ptr(output, n);
4819 }
4820 }
4821
4822 if (ended_with_ifs)
4823 *ended_with_ifs = last_is_ifs;
4824 debug_print_list("expand_on_ifs[1]", output, n);
4825 return n;
4826}
4827
4828/* Helper to expand $((...)) and heredoc body. These act as if
4829 * they are in double quotes, with the exception that they are not :).
4830 * Just the rules are similar: "expand only $var and `cmd`"
4831 *
4832 * Returns malloced string.
4833 * As an optimization, we return NULL if expansion is not needed.
4834 */
4835#if !ENABLE_HUSH_BASH_COMPAT
4836/* only ${var/pattern/repl} (its pattern part) needs additional mode */
4837#define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4838 encode_then_expand_string(str)
4839#endif
4840static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4841{
4842 char *exp_str;
4843 struct in_str input;
4844 o_string dest = NULL_O_STRING;
4845
4846 if (!strchr(str, '$')
4847 && !strchr(str, '\\')
4848#if ENABLE_HUSH_TICK
4849 && !strchr(str, '`')
4850#endif
4851 ) {
4852 return NULL;
4853 }
4854
4855 /* We need to expand. Example:
4856 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4857 */
4858 setup_string_in_str(&input, str);
4859 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4860//TODO: error check (encode_string returns 0 on error)?
4861 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4862 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4863 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4864 o_free_unsafe(&dest);
4865 return exp_str;
4866}
4867
4868#if ENABLE_SH_MATH_SUPPORT
4869static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
4870{
4871 arith_state_t math_state;
4872 arith_t res;
4873 char *exp_str;
4874
4875 math_state.lookupvar = get_local_var_value;
4876 math_state.setvar = set_local_var_from_halves;
4877 //math_state.endofname = endofname;
4878 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4879 res = arith(&math_state, exp_str ? exp_str : arg);
4880 free(exp_str);
4881 if (errmsg_p)
4882 *errmsg_p = math_state.errmsg;
4883 if (math_state.errmsg)
4884 die_if_script(math_state.errmsg);
4885 return res;
4886}
4887#endif
4888
4889#if ENABLE_HUSH_BASH_COMPAT
4890/* ${var/[/]pattern[/repl]} helpers */
4891static char *strstr_pattern(char *val, const char *pattern, int *size)
4892{
4893 while (1) {
4894 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4895 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4896 if (end) {
4897 *size = end - val;
4898 return val;
4899 }
4900 if (*val == '\0')
4901 return NULL;
4902 /* Optimization: if "*pat" did not match the start of "string",
4903 * we know that "tring", "ring" etc will not match too:
4904 */
4905 if (pattern[0] == '*')
4906 return NULL;
4907 val++;
4908 }
4909}
4910static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4911{
4912 char *result = NULL;
4913 unsigned res_len = 0;
4914 unsigned repl_len = strlen(repl);
4915
4916 while (1) {
4917 int size;
4918 char *s = strstr_pattern(val, pattern, &size);
4919 if (!s)
4920 break;
4921
4922 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4923 memcpy(result + res_len, val, s - val);
4924 res_len += s - val;
4925 strcpy(result + res_len, repl);
4926 res_len += repl_len;
4927 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4928
4929 val = s + size;
4930 if (exp_op == '/')
4931 break;
4932 }
4933 if (val[0] && result) {
4934 result = xrealloc(result, res_len + strlen(val) + 1);
4935 strcpy(result + res_len, val);
4936 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4937 }
4938 debug_printf_varexp("result:'%s'\n", result);
4939 return result;
4940}
4941#endif
4942
4943/* Helper:
4944 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4945 */
4946static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4947{
4948 const char *val = NULL;
4949 char *to_be_freed = NULL;
4950 char *p = *pp;
4951 char *var;
4952 char first_char;
4953 char exp_op;
4954 char exp_save = exp_save; /* for compiler */
4955 char *exp_saveptr; /* points to expansion operator */
4956 char *exp_word = exp_word; /* for compiler */
4957 char arg0;
4958
4959 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4960 var = arg;
4961 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4962 arg0 = arg[0];
4963 first_char = arg[0] = arg0 & 0x7f;
4964 exp_op = 0;
4965
4966 if (first_char == '#' /* ${#... */
4967 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4968 ) {
4969 /* It must be length operator: ${#var} */
4970 var++;
4971 exp_op = 'L';
4972 } else {
4973 /* Maybe handle parameter expansion */
4974 if (exp_saveptr /* if 2nd char is one of expansion operators */
4975 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4976 ) {
4977 /* ${?:0}, ${#[:]%0} etc */
4978 exp_saveptr = var + 1;
4979 } else {
4980 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4981 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4982 }
4983 exp_op = exp_save = *exp_saveptr;
4984 if (exp_op) {
4985 exp_word = exp_saveptr + 1;
4986 if (exp_op == ':') {
4987 exp_op = *exp_word++;
4988//TODO: try ${var:} and ${var:bogus} in non-bash config
4989 if (ENABLE_HUSH_BASH_COMPAT
4990 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4991 ) {
4992 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4993 exp_op = ':';
4994 exp_word--;
4995 }
4996 }
4997 *exp_saveptr = '\0';
4998 } /* else: it's not an expansion op, but bare ${var} */
4999 }
5000
5001 /* Look up the variable in question */
5002 if (isdigit(var[0])) {
5003 /* parse_dollar should have vetted var for us */
5004 int n = xatoi_positive(var);
5005 if (n < G.global_argc)
5006 val = G.global_argv[n];
5007 /* else val remains NULL: $N with too big N */
5008 } else {
5009 switch (var[0]) {
5010 case '$': /* pid */
5011 val = utoa(G.root_pid);
5012 break;
5013 case '!': /* bg pid */
5014 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5015 break;
5016 case '?': /* exitcode */
5017 val = utoa(G.last_exitcode);
5018 break;
5019 case '#': /* argc */
5020 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5021 break;
5022 default:
5023 val = get_local_var_value(var);
5024 }
5025 }
5026
5027 /* Handle any expansions */
5028 if (exp_op == 'L') {
5029 debug_printf_expand("expand: length(%s)=", val);
5030 val = utoa(val ? strlen(val) : 0);
5031 debug_printf_expand("%s\n", val);
5032 } else if (exp_op) {
5033 if (exp_op == '%' || exp_op == '#') {
5034 /* Standard-mandated substring removal ops:
5035 * ${parameter%word} - remove smallest suffix pattern
5036 * ${parameter%%word} - remove largest suffix pattern
5037 * ${parameter#word} - remove smallest prefix pattern
5038 * ${parameter##word} - remove largest prefix pattern
5039 *
5040 * Word is expanded to produce a glob pattern.
5041 * Then var's value is matched to it and matching part removed.
5042 */
5043 if (val && val[0]) {
5044 char *t;
5045 char *exp_exp_word;
5046 char *loc;
5047 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5048 if (exp_op == *exp_word) /* ## or %% */
5049 exp_word++;
5050 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5051 if (exp_exp_word)
5052 exp_word = exp_exp_word;
5053 /* HACK ALERT. We depend here on the fact that
5054 * G.global_argv and results of utoa and get_local_var_value
5055 * are actually in writable memory:
5056 * scan_and_match momentarily stores NULs there. */
5057 t = (char*)val;
5058 loc = scan_and_match(t, exp_word, scan_flags);
5059 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5060 // exp_op, t, exp_word, loc);
5061 free(exp_exp_word);
5062 if (loc) { /* match was found */
5063 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5064 val = loc; /* take right part */
5065 else /* %[%] */
5066 val = to_be_freed = xstrndup(val, loc - val); /* left */
5067 }
5068 }
5069 }
5070#if ENABLE_HUSH_BASH_COMPAT
5071 else if (exp_op == '/' || exp_op == '\\') {
5072 /* It's ${var/[/]pattern[/repl]} thing.
5073 * Note that in encoded form it has TWO parts:
5074 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5075 * and if // is used, it is encoded as \:
5076 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5077 */
5078 /* Empty variable always gives nothing: */
5079 // "v=''; echo ${v/*/w}" prints "", not "w"
5080 if (val && val[0]) {
5081 /* pattern uses non-standard expansion.
5082 * repl should be unbackslashed and globbed
5083 * by the usual expansion rules:
5084 * >az; >bz;
5085 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5086 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5087 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5088 * v='a bz'; echo ${v/a*z/\z} prints "z"
5089 * (note that a*z _pattern_ is never globbed!)
5090 */
5091 char *pattern, *repl, *t;
5092 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5093 if (!pattern)
5094 pattern = xstrdup(exp_word);
5095 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5096 *p++ = SPECIAL_VAR_SYMBOL;
5097 exp_word = p;
5098 p = strchr(p, SPECIAL_VAR_SYMBOL);
5099 *p = '\0';
5100 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5101 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5102 /* HACK ALERT. We depend here on the fact that
5103 * G.global_argv and results of utoa and get_local_var_value
5104 * are actually in writable memory:
5105 * replace_pattern momentarily stores NULs there. */
5106 t = (char*)val;
5107 to_be_freed = replace_pattern(t,
5108 pattern,
5109 (repl ? repl : exp_word),
5110 exp_op);
5111 if (to_be_freed) /* at least one replace happened */
5112 val = to_be_freed;
5113 free(pattern);
5114 free(repl);
5115 }
5116 }
5117#endif
5118 else if (exp_op == ':') {
5119#if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5120 /* It's ${var:N[:M]} bashism.
5121 * Note that in encoded form it has TWO parts:
5122 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5123 */
5124 arith_t beg, len;
5125 const char *errmsg;
5126
5127 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5128 if (errmsg)
5129 goto arith_err;
5130 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5131 *p++ = SPECIAL_VAR_SYMBOL;
5132 exp_word = p;
5133 p = strchr(p, SPECIAL_VAR_SYMBOL);
5134 *p = '\0';
5135 len = expand_and_evaluate_arith(exp_word, &errmsg);
5136 if (errmsg)
5137 goto arith_err;
5138 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5139 if (len >= 0) { /* bash compat: len < 0 is illegal */
5140 if (beg < 0) /* bash compat */
5141 beg = 0;
5142 debug_printf_varexp("from val:'%s'\n", val);
5143 if (len == 0 || !val || beg >= strlen(val)) {
5144 arith_err:
5145 val = NULL;
5146 } else {
5147 /* Paranoia. What if user entered 9999999999999
5148 * which fits in arith_t but not int? */
5149 if (len >= INT_MAX)
5150 len = INT_MAX;
5151 val = to_be_freed = xstrndup(val + beg, len);
5152 }
5153 debug_printf_varexp("val:'%s'\n", val);
5154 } else
5155#endif
5156 {
5157 die_if_script("malformed ${%s:...}", var);
5158 val = NULL;
5159 }
5160 } else { /* one of "-=+?" */
5161 /* Standard-mandated substitution ops:
5162 * ${var?word} - indicate error if unset
5163 * If var is unset, word (or a message indicating it is unset
5164 * if word is null) is written to standard error
5165 * and the shell exits with a non-zero exit status.
5166 * Otherwise, the value of var is substituted.
5167 * ${var-word} - use default value
5168 * If var is unset, word is substituted.
5169 * ${var=word} - assign and use default value
5170 * If var is unset, word is assigned to var.
5171 * In all cases, final value of var is substituted.
5172 * ${var+word} - use alternative value
5173 * If var is unset, null is substituted.
5174 * Otherwise, word is substituted.
5175 *
5176 * Word is subjected to tilde expansion, parameter expansion,
5177 * command substitution, and arithmetic expansion.
5178 * If word is not needed, it is not expanded.
5179 *
5180 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5181 * but also treat null var as if it is unset.
5182 */
5183 int use_word = (!val || ((exp_save == ':') && !val[0]));
5184 if (exp_op == '+')
5185 use_word = !use_word;
5186 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5187 (exp_save == ':') ? "true" : "false", use_word);
5188 if (use_word) {
5189 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5190 if (to_be_freed)
5191 exp_word = to_be_freed;
5192 if (exp_op == '?') {
5193 /* mimic bash message */
5194 die_if_script("%s: %s",
5195 var,
5196 exp_word[0] ? exp_word : "parameter null or not set"
5197 );
5198//TODO: how interactive bash aborts expansion mid-command?
5199 } else {
5200 val = exp_word;
5201 }
5202
5203 if (exp_op == '=') {
5204 /* ${var=[word]} or ${var:=[word]} */
5205 if (isdigit(var[0]) || var[0] == '#') {
5206 /* mimic bash message */
5207 die_if_script("$%s: cannot assign in this way", var);
5208 val = NULL;
5209 } else {
5210 char *new_var = xasprintf("%s=%s", var, val);
5211 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5212 }
5213 }
5214 }
5215 } /* one of "-=+?" */
5216
5217 *exp_saveptr = exp_save;
5218 } /* if (exp_op) */
5219
5220 arg[0] = arg0;
5221
5222 *pp = p;
5223 *to_be_freed_pp = to_be_freed;
5224 return val;
5225}
5226
5227/* Expand all variable references in given string, adding words to list[]
5228 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5229 * to be filled). This routine is extremely tricky: has to deal with
5230 * variables/parameters with whitespace, $* and $@, and constructs like
5231 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5232static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5233{
5234 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5235 * expansion of right-hand side of assignment == 1-element expand.
5236 */
5237 char cant_be_null = 0; /* only bit 0x80 matters */
5238 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5239 char *p;
5240
5241 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5242 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5243 debug_print_list("expand_vars_to_list", output, n);
5244 n = o_save_ptr(output, n);
5245 debug_print_list("expand_vars_to_list[0]", output, n);
5246
5247 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5248 char first_ch;
5249 char *to_be_freed = NULL;
5250 const char *val = NULL;
5251#if ENABLE_HUSH_TICK
5252 o_string subst_result = NULL_O_STRING;
5253#endif
5254#if ENABLE_SH_MATH_SUPPORT
5255 char arith_buf[sizeof(arith_t)*3 + 2];
5256#endif
5257
5258 if (ended_in_ifs) {
5259 o_addchr(output, '\0');
5260 n = o_save_ptr(output, n);
5261 ended_in_ifs = 0;
5262 }
5263
5264 o_addblock(output, arg, p - arg);
5265 debug_print_list("expand_vars_to_list[1]", output, n);
5266 arg = ++p;
5267 p = strchr(p, SPECIAL_VAR_SYMBOL);
5268
5269 /* Fetch special var name (if it is indeed one of them)
5270 * and quote bit, force the bit on if singleword expansion -
5271 * important for not getting v=$@ expand to many words. */
5272 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5273
5274 /* Is this variable quoted and thus expansion can't be null?
5275 * "$@" is special. Even if quoted, it can still
5276 * expand to nothing (not even an empty string),
5277 * thus it is excluded. */
5278 if ((first_ch & 0x7f) != '@')
5279 cant_be_null |= first_ch;
5280
5281 switch (first_ch & 0x7f) {
5282 /* Highest bit in first_ch indicates that var is double-quoted */
5283 case '*':
5284 case '@': {
5285 int i;
5286 if (!G.global_argv[1])
5287 break;
5288 i = 1;
5289 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5290 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5291 while (G.global_argv[i]) {
5292 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5293 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5294 if (G.global_argv[i++][0] && G.global_argv[i]) {
5295 /* this argv[] is not empty and not last:
5296 * put terminating NUL, start new word */
5297 o_addchr(output, '\0');
5298 debug_print_list("expand_vars_to_list[2]", output, n);
5299 n = o_save_ptr(output, n);
5300 debug_print_list("expand_vars_to_list[3]", output, n);
5301 }
5302 }
5303 } else
5304 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5305 * and in this case should treat it like '$*' - see 'else...' below */
5306 if (first_ch == ('@'|0x80) /* quoted $@ */
5307 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5308 ) {
5309 while (1) {
5310 o_addQstr(output, G.global_argv[i]);
5311 if (++i >= G.global_argc)
5312 break;
5313 o_addchr(output, '\0');
5314 debug_print_list("expand_vars_to_list[4]", output, n);
5315 n = o_save_ptr(output, n);
5316 }
5317 } else { /* quoted $* (or v="$@" case): add as one word */
5318 while (1) {
5319 o_addQstr(output, G.global_argv[i]);
5320 if (!G.global_argv[++i])
5321 break;
5322 if (G.ifs[0])
5323 o_addchr(output, G.ifs[0]);
5324 }
5325 output->has_quoted_part = 1;
5326 }
5327 break;
5328 }
5329 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5330 /* "Empty variable", used to make "" etc to not disappear */
5331 output->has_quoted_part = 1;
5332 arg++;
5333 cant_be_null = 0x80;
5334 break;
5335#if ENABLE_HUSH_TICK
5336 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5337 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5338 arg++;
5339 /* Can't just stuff it into output o_string,
5340 * expanded result may need to be globbed
5341 * and $IFS-splitted */
5342 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5343 G.last_exitcode = process_command_subs(&subst_result, arg);
5344 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5345 val = subst_result.data;
5346 goto store_val;
5347#endif
5348#if ENABLE_SH_MATH_SUPPORT
5349 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5350 arith_t res;
5351
5352 arg++; /* skip '+' */
5353 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5354 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5355 res = expand_and_evaluate_arith(arg, NULL);
5356 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5357 sprintf(arith_buf, ARITH_FMT, res);
5358 val = arith_buf;
5359 break;
5360 }
5361#endif
5362 default:
5363 val = expand_one_var(&to_be_freed, arg, &p);
5364 IF_HUSH_TICK(store_val:)
5365 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5366 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5367 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5368 if (val && val[0]) {
5369 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5370 val = NULL;
5371 }
5372 } else { /* quoted $VAR, val will be appended below */
5373 output->has_quoted_part = 1;
5374 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5375 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5376 }
5377 break;
5378
5379 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5380
5381 if (val && val[0]) {
5382 o_addQstr(output, val);
5383 }
5384 free(to_be_freed);
5385
5386 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5387 * Do the check to avoid writing to a const string. */
5388 if (*p != SPECIAL_VAR_SYMBOL)
5389 *p = SPECIAL_VAR_SYMBOL;
5390
5391#if ENABLE_HUSH_TICK
5392 o_free(&subst_result);
5393#endif
5394 arg = ++p;
5395 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5396
5397 if (arg[0]) {
5398 if (ended_in_ifs) {
5399 o_addchr(output, '\0');
5400 n = o_save_ptr(output, n);
5401 }
5402 debug_print_list("expand_vars_to_list[a]", output, n);
5403 /* this part is literal, and it was already pre-quoted
5404 * if needed (much earlier), do not use o_addQstr here! */
5405 o_addstr_with_NUL(output, arg);
5406 debug_print_list("expand_vars_to_list[b]", output, n);
5407 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5408 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5409 ) {
5410 n--;
5411 /* allow to reuse list[n] later without re-growth */
5412 output->has_empty_slot = 1;
5413 } else {
5414 o_addchr(output, '\0');
5415 }
5416
5417 return n;
5418}
5419
5420static char **expand_variables(char **argv, unsigned expflags)
5421{
5422 int n;
5423 char **list;
5424 o_string output = NULL_O_STRING;
5425
5426 output.o_expflags = expflags;
5427
5428 n = 0;
5429 while (*argv) {
5430 n = expand_vars_to_list(&output, n, *argv);
5431 argv++;
5432 }
5433 debug_print_list("expand_variables", &output, n);
5434
5435 /* output.data (malloced in one block) gets returned in "list" */
5436 list = o_finalize_list(&output, n);
5437 debug_print_strings("expand_variables[1]", list);
5438 return list;
5439}
5440
5441static char **expand_strvec_to_strvec(char **argv)
5442{
5443 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5444}
5445
5446#if ENABLE_HUSH_BASH_COMPAT
5447static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5448{
5449 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5450}
5451#endif
5452
5453/* Used for expansion of right hand of assignments,
5454 * $((...)), heredocs, variable espansion parts.
5455 *
5456 * NB: should NOT do globbing!
5457 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5458 */
5459static char *expand_string_to_string(const char *str, int do_unbackslash)
5460{
5461#if !ENABLE_HUSH_BASH_COMPAT
5462 const int do_unbackslash = 1;
5463#endif
5464 char *argv[2], **list;
5465
5466 debug_printf_expand("string_to_string<='%s'\n", str);
5467 /* This is generally an optimization, but it also
5468 * handles "", which otherwise trips over !list[0] check below.
5469 * (is this ever happens that we actually get str="" here?)
5470 */
5471 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5472 //TODO: Can use on strings with \ too, just unbackslash() them?
5473 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5474 return xstrdup(str);
5475 }
5476
5477 argv[0] = (char*)str;
5478 argv[1] = NULL;
5479 list = expand_variables(argv, do_unbackslash
5480 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5481 : EXP_FLAG_SINGLEWORD
5482 );
5483 if (HUSH_DEBUG)
5484 if (!list[0] || list[1])
5485 bb_error_msg_and_die("BUG in varexp2");
5486 /* actually, just move string 2*sizeof(char*) bytes back */
5487 overlapping_strcpy((char*)list, list[0]);
5488 if (do_unbackslash)
5489 unbackslash((char*)list);
5490 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5491 return (char*)list;
5492}
5493
5494/* Used for "eval" builtin */
5495static char* expand_strvec_to_string(char **argv)
5496{
5497 char **list;
5498
5499 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5500 /* Convert all NULs to spaces */
5501 if (list[0]) {
5502 int n = 1;
5503 while (list[n]) {
5504 if (HUSH_DEBUG)
5505 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5506 bb_error_msg_and_die("BUG in varexp3");
5507 /* bash uses ' ' regardless of $IFS contents */
5508 list[n][-1] = ' ';
5509 n++;
5510 }
5511 }
5512 overlapping_strcpy((char*)list, list[0]);
5513 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5514 return (char*)list;
5515}
5516
5517static char **expand_assignments(char **argv, int count)
5518{
5519 int i;
5520 char **p;
5521
5522 G.expanded_assignments = p = NULL;
5523 /* Expand assignments into one string each */
5524 for (i = 0; i < count; i++) {
5525 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5526 }
5527 G.expanded_assignments = NULL;
5528 return p;
5529}
5530
5531
5532static void switch_off_special_sigs(unsigned mask)
5533{
5534 unsigned sig = 0;
5535 while ((mask >>= 1) != 0) {
5536 sig++;
5537 if (!(mask & 1))
5538 continue;
5539 if (G.traps) {
5540 if (G.traps[sig] && !G.traps[sig][0])
5541 /* trap is '', has to remain SIG_IGN */
5542 continue;
5543 free(G.traps[sig]);
5544 G.traps[sig] = NULL;
5545 }
5546 /* We are here only if no trap or trap was not '' */
5547 install_sighandler(sig, SIG_DFL);
5548 }
5549}
5550
5551#if BB_MMU
5552/* never called */
5553void re_execute_shell(char ***to_free, const char *s,
5554 char *g_argv0, char **g_argv,
5555 char **builtin_argv) NORETURN;
5556
5557static void reset_traps_to_defaults(void)
5558{
5559 /* This function is always called in a child shell
5560 * after fork (not vfork, NOMMU doesn't use this function).
5561 */
5562 unsigned sig;
5563 unsigned mask;
5564
5565 /* Child shells are not interactive.
5566 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5567 * Testcase: (while :; do :; done) + ^Z should background.
5568 * Same goes for SIGTERM, SIGHUP, SIGINT.
5569 */
5570 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5571 if (!G.traps && !mask)
5572 return; /* already no traps and no special sigs */
5573
5574 /* Switch off special sigs */
5575 switch_off_special_sigs(mask);
5576#if ENABLE_HUSH_JOB
5577 G_fatal_sig_mask = 0;
5578#endif
5579 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5580 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5581 * remain set in G.special_sig_mask */
5582
5583 if (!G.traps)
5584 return;
5585
5586 /* Reset all sigs to default except ones with empty traps */
5587 for (sig = 0; sig < NSIG; sig++) {
5588 if (!G.traps[sig])
5589 continue; /* no trap: nothing to do */
5590 if (!G.traps[sig][0])
5591 continue; /* empty trap: has to remain SIG_IGN */
5592 /* sig has non-empty trap, reset it: */
5593 free(G.traps[sig]);
5594 G.traps[sig] = NULL;
5595 /* There is no signal for trap 0 (EXIT) */
5596 if (sig == 0)
5597 continue;
5598 install_sighandler(sig, pick_sighandler(sig));
5599 }
5600}
5601
5602#else /* !BB_MMU */
5603
5604static void re_execute_shell(char ***to_free, const char *s,
5605 char *g_argv0, char **g_argv,
5606 char **builtin_argv) NORETURN;
5607static void re_execute_shell(char ***to_free, const char *s,
5608 char *g_argv0, char **g_argv,
5609 char **builtin_argv)
5610{
5611# define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5612 /* delims + 2 * (number of bytes in printed hex numbers) */
5613 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5614 char *heredoc_argv[4];
5615 struct variable *cur;
5616# if ENABLE_HUSH_FUNCTIONS
5617 struct function *funcp;
5618# endif
5619 char **argv, **pp;
5620 unsigned cnt;
5621 unsigned long long empty_trap_mask;
5622
5623 if (!g_argv0) { /* heredoc */
5624 argv = heredoc_argv;
5625 argv[0] = (char *) G.argv0_for_re_execing;
5626 argv[1] = (char *) "-<";
5627 argv[2] = (char *) s;
5628 argv[3] = NULL;
5629 pp = &argv[3]; /* used as pointer to empty environment */
5630 goto do_exec;
5631 }
5632
5633 cnt = 0;
5634 pp = builtin_argv;
5635 if (pp) while (*pp++)
5636 cnt++;
5637
5638 empty_trap_mask = 0;
5639 if (G.traps) {
5640 int sig;
5641 for (sig = 1; sig < NSIG; sig++) {
5642 if (G.traps[sig] && !G.traps[sig][0])
5643 empty_trap_mask |= 1LL << sig;
5644 }
5645 }
5646
5647 sprintf(param_buf, NOMMU_HACK_FMT
5648 , (unsigned) G.root_pid
5649 , (unsigned) G.root_ppid
5650 , (unsigned) G.last_bg_pid
5651 , (unsigned) G.last_exitcode
5652 , cnt
5653 , empty_trap_mask
5654 IF_HUSH_LOOPS(, G.depth_of_loop)
5655 );
5656# undef NOMMU_HACK_FMT
5657 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5658 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5659 */
5660 cnt += 6;
5661 for (cur = G.top_var; cur; cur = cur->next) {
5662 if (!cur->flg_export || cur->flg_read_only)
5663 cnt += 2;
5664 }
5665# if ENABLE_HUSH_FUNCTIONS
5666 for (funcp = G.top_func; funcp; funcp = funcp->next)
5667 cnt += 3;
5668# endif
5669 pp = g_argv;
5670 while (*pp++)
5671 cnt++;
5672 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5673 *pp++ = (char *) G.argv0_for_re_execing;
5674 *pp++ = param_buf;
5675 for (cur = G.top_var; cur; cur = cur->next) {
5676 if (strcmp(cur->varstr, hush_version_str) == 0)
5677 continue;
5678 if (cur->flg_read_only) {
5679 *pp++ = (char *) "-R";
5680 *pp++ = cur->varstr;
5681 } else if (!cur->flg_export) {
5682 *pp++ = (char *) "-V";
5683 *pp++ = cur->varstr;
5684 }
5685 }
5686# if ENABLE_HUSH_FUNCTIONS
5687 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5688 *pp++ = (char *) "-F";
5689 *pp++ = funcp->name;
5690 *pp++ = funcp->body_as_string;
5691 }
5692# endif
5693 /* We can pass activated traps here. Say, -Tnn:trap_string
5694 *
5695 * However, POSIX says that subshells reset signals with traps
5696 * to SIG_DFL.
5697 * I tested bash-3.2 and it not only does that with true subshells
5698 * of the form ( list ), but with any forked children shells.
5699 * I set trap "echo W" WINCH; and then tried:
5700 *
5701 * { echo 1; sleep 20; echo 2; } &
5702 * while true; do echo 1; sleep 20; echo 2; break; done &
5703 * true | { echo 1; sleep 20; echo 2; } | cat
5704 *
5705 * In all these cases sending SIGWINCH to the child shell
5706 * did not run the trap. If I add trap "echo V" WINCH;
5707 * _inside_ group (just before echo 1), it works.
5708 *
5709 * I conclude it means we don't need to pass active traps here.
5710 */
5711 *pp++ = (char *) "-c";
5712 *pp++ = (char *) s;
5713 if (builtin_argv) {
5714 while (*++builtin_argv)
5715 *pp++ = *builtin_argv;
5716 *pp++ = (char *) "";
5717 }
5718 *pp++ = g_argv0;
5719 while (*g_argv)
5720 *pp++ = *g_argv++;
5721 /* *pp = NULL; - is already there */
5722 pp = environ;
5723
5724 do_exec:
5725 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5726 /* Don't propagate SIG_IGN to the child */
5727 if (SPECIAL_JOBSTOP_SIGS != 0)
5728 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
5729 execve(bb_busybox_exec_path, argv, pp);
5730 /* Fallback. Useful for init=/bin/hush usage etc */
5731 if (argv[0][0] == '/')
5732 execve(argv[0], argv, pp);
5733 xfunc_error_retval = 127;
5734 bb_error_msg_and_die("can't re-execute the shell");
5735}
5736#endif /* !BB_MMU */
5737
5738
5739static int run_and_free_list(struct pipe *pi);
5740
5741/* Executing from string: eval, sh -c '...'
5742 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5743 * end_trigger controls how often we stop parsing
5744 * NUL: parse all, execute, return
5745 * ';': parse till ';' or newline, execute, repeat till EOF
5746 */
5747static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5748{
5749 /* Why we need empty flag?
5750 * An obscure corner case "false; ``; echo $?":
5751 * empty command in `` should still set $? to 0.
5752 * But we can't just set $? to 0 at the start,
5753 * this breaks "false; echo `echo $?`" case.
5754 */
5755 bool empty = 1;
5756 while (1) {
5757 struct pipe *pipe_list;
5758
5759#if ENABLE_HUSH_INTERACTIVE
5760 if (end_trigger == ';')
5761 inp->promptmode = 0; /* PS1 */
5762#endif
5763 pipe_list = parse_stream(NULL, inp, end_trigger);
5764 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
5765 /* If we are in "big" script
5766 * (not in `cmd` or something similar)...
5767 */
5768 if (pipe_list == ERR_PTR && end_trigger == ';') {
5769 /* Discard cached input (rest of line) */
5770 int ch = inp->last_char;
5771 while (ch != EOF && ch != '\n') {
5772 //bb_error_msg("Discarded:'%c'", ch);
5773 ch = i_getch(inp);
5774 }
5775 /* Force prompt */
5776 inp->p = NULL;
5777 /* This stream isn't empty */
5778 empty = 0;
5779 continue;
5780 }
5781 if (!pipe_list && empty)
5782 G.last_exitcode = 0;
5783 break;
5784 }
5785 debug_print_tree(pipe_list, 0);
5786 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5787 run_and_free_list(pipe_list);
5788 empty = 0;
5789#if ENABLE_HUSH_FUNCTIONS
5790 if (G.flag_return_in_progress == 1)
5791 break;
5792#endif
5793 }
5794}
5795
5796static void parse_and_run_string(const char *s)
5797{
5798 struct in_str input;
5799 setup_string_in_str(&input, s);
5800 parse_and_run_stream(&input, '\0');
5801}
5802
5803static void parse_and_run_file(FILE *f)
5804{
5805 struct in_str input;
5806 setup_file_in_str(&input, f);
5807 parse_and_run_stream(&input, ';');
5808}
5809
5810#if ENABLE_HUSH_TICK
5811static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5812{
5813 pid_t pid;
5814 int channel[2];
5815# if !BB_MMU
5816 char **to_free = NULL;
5817# endif
5818
5819 xpipe(channel);
5820 pid = BB_MMU ? xfork() : xvfork();
5821 if (pid == 0) { /* child */
5822 disable_restore_tty_pgrp_on_exit();
5823 /* Process substitution is not considered to be usual
5824 * 'command execution'.
5825 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5826 */
5827 bb_signals(0
5828 + (1 << SIGTSTP)
5829 + (1 << SIGTTIN)
5830 + (1 << SIGTTOU)
5831 , SIG_IGN);
5832 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5833 close(channel[0]); /* NB: close _first_, then move fd! */
5834 xmove_fd(channel[1], 1);
5835 /* Prevent it from trying to handle ctrl-z etc */
5836 IF_HUSH_JOB(G.run_list_level = 1;)
5837 /* Awful hack for `trap` or $(trap).
5838 *
5839 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5840 * contains an example where "trap" is executed in a subshell:
5841 *
5842 * save_traps=$(trap)
5843 * ...
5844 * eval "$save_traps"
5845 *
5846 * Standard does not say that "trap" in subshell shall print
5847 * parent shell's traps. It only says that its output
5848 * must have suitable form, but then, in the above example
5849 * (which is not supposed to be normative), it implies that.
5850 *
5851 * bash (and probably other shell) does implement it
5852 * (traps are reset to defaults, but "trap" still shows them),
5853 * but as a result, "trap" logic is hopelessly messed up:
5854 *
5855 * # trap
5856 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5857 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5858 * # true | trap <--- trap is in subshell - no output (ditto)
5859 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5860 * trap -- 'echo Ho' SIGWINCH
5861 * # echo `(trap)` <--- in subshell in subshell - output
5862 * trap -- 'echo Ho' SIGWINCH
5863 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5864 * trap -- 'echo Ho' SIGWINCH
5865 *
5866 * The rules when to forget and when to not forget traps
5867 * get really complex and nonsensical.
5868 *
5869 * Our solution: ONLY bare $(trap) or `trap` is special.
5870 */
5871 s = skip_whitespace(s);
5872 if (strncmp(s, "trap", 4) == 0
5873 && skip_whitespace(s + 4)[0] == '\0'
5874 ) {
5875 static const char *const argv[] = { NULL, NULL };
5876 builtin_trap((char**)argv);
5877 exit(0); /* not _exit() - we need to fflush */
5878 }
5879# if BB_MMU
5880 reset_traps_to_defaults();
5881 parse_and_run_string(s);
5882 _exit(G.last_exitcode);
5883# else
5884 /* We re-execute after vfork on NOMMU. This makes this script safe:
5885 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5886 * huge=`cat BIG` # was blocking here forever
5887 * echo OK
5888 */
5889 re_execute_shell(&to_free,
5890 s,
5891 G.global_argv[0],
5892 G.global_argv + 1,
5893 NULL);
5894# endif
5895 }
5896
5897 /* parent */
5898 *pid_p = pid;
5899# if ENABLE_HUSH_FAST
5900 G.count_SIGCHLD++;
5901//bb_error_msg("[%d] fork in generate_stream_from_string:"
5902// " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5903// getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5904# endif
5905 enable_restore_tty_pgrp_on_exit();
5906# if !BB_MMU
5907 free(to_free);
5908# endif
5909 close(channel[1]);
5910 close_on_exec_on(channel[0]);
5911 return xfdopen_for_read(channel[0]);
5912}
5913
5914/* Return code is exit status of the process that is run. */
5915static int process_command_subs(o_string *dest, const char *s)
5916{
5917 FILE *fp;
5918 struct in_str pipe_str;
5919 pid_t pid;
5920 int status, ch, eol_cnt;
5921
5922 fp = generate_stream_from_string(s, &pid);
5923
5924 /* Now send results of command back into original context */
5925 setup_file_in_str(&pipe_str, fp);
5926 eol_cnt = 0;
5927 while ((ch = i_getch(&pipe_str)) != EOF) {
5928 if (ch == '\n') {
5929 eol_cnt++;
5930 continue;
5931 }
5932 while (eol_cnt) {
5933 o_addchr(dest, '\n');
5934 eol_cnt--;
5935 }
5936 o_addQchr(dest, ch);
5937 }
5938
5939 debug_printf("done reading from `cmd` pipe, closing it\n");
5940 fclose(fp);
5941 /* We need to extract exitcode. Test case
5942 * "true; echo `sleep 1; false` $?"
5943 * should print 1 */
5944 safe_waitpid(pid, &status, 0);
5945 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5946 return WEXITSTATUS(status);
5947}
5948#endif /* ENABLE_HUSH_TICK */
5949
5950
5951static void setup_heredoc(struct redir_struct *redir)
5952{
5953 struct fd_pair pair;
5954 pid_t pid;
5955 int len, written;
5956 /* the _body_ of heredoc (misleading field name) */
5957 const char *heredoc = redir->rd_filename;
5958 char *expanded;
5959#if !BB_MMU
5960 char **to_free;
5961#endif
5962
5963 expanded = NULL;
5964 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5965 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5966 if (expanded)
5967 heredoc = expanded;
5968 }
5969 len = strlen(heredoc);
5970
5971 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5972 xpiped_pair(pair);
5973 xmove_fd(pair.rd, redir->rd_fd);
5974
5975 /* Try writing without forking. Newer kernels have
5976 * dynamically growing pipes. Must use non-blocking write! */
5977 ndelay_on(pair.wr);
5978 while (1) {
5979 written = write(pair.wr, heredoc, len);
5980 if (written <= 0)
5981 break;
5982 len -= written;
5983 if (len == 0) {
5984 close(pair.wr);
5985 free(expanded);
5986 return;
5987 }
5988 heredoc += written;
5989 }
5990 ndelay_off(pair.wr);
5991
5992 /* Okay, pipe buffer was not big enough */
5993 /* Note: we must not create a stray child (bastard? :)
5994 * for the unsuspecting parent process. Child creates a grandchild
5995 * and exits before parent execs the process which consumes heredoc
5996 * (that exec happens after we return from this function) */
5997#if !BB_MMU
5998 to_free = NULL;
5999#endif
6000 pid = xvfork();
6001 if (pid == 0) {
6002 /* child */
6003 disable_restore_tty_pgrp_on_exit();
6004 pid = BB_MMU ? xfork() : xvfork();
6005 if (pid != 0)
6006 _exit(0);
6007 /* grandchild */
6008 close(redir->rd_fd); /* read side of the pipe */
6009#if BB_MMU
6010 full_write(pair.wr, heredoc, len); /* may loop or block */
6011 _exit(0);
6012#else
6013 /* Delegate blocking writes to another process */
6014 xmove_fd(pair.wr, STDOUT_FILENO);
6015 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6016#endif
6017 }
6018 /* parent */
6019#if ENABLE_HUSH_FAST
6020 G.count_SIGCHLD++;
6021//bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6022#endif
6023 enable_restore_tty_pgrp_on_exit();
6024#if !BB_MMU
6025 free(to_free);
6026#endif
6027 close(pair.wr);
6028 free(expanded);
6029 wait(NULL); /* wait till child has died */
6030}
6031
6032/* squirrel != NULL means we squirrel away copies of stdin, stdout,
6033 * and stderr if they are redirected. */
6034static int setup_redirects(struct command *prog, int squirrel[])
6035{
6036 int openfd, mode;
6037 struct redir_struct *redir;
6038
6039 for (redir = prog->redirects; redir; redir = redir->next) {
6040 if (redir->rd_type == REDIRECT_HEREDOC2) {
6041 /* rd_fd<<HERE case */
6042 if (squirrel && redir->rd_fd < 3
6043 && squirrel[redir->rd_fd] < 0
6044 ) {
6045 squirrel[redir->rd_fd] = dup(redir->rd_fd);
6046 }
6047 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6048 * of the heredoc */
6049 debug_printf_parse("set heredoc '%s'\n",
6050 redir->rd_filename);
6051 setup_heredoc(redir);
6052 continue;
6053 }
6054
6055 if (redir->rd_dup == REDIRFD_TO_FILE) {
6056 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
6057 char *p;
6058 if (redir->rd_filename == NULL) {
6059 /* Something went wrong in the parse.
6060 * Pretend it didn't happen */
6061 bb_error_msg("bug in redirect parse");
6062 continue;
6063 }
6064 mode = redir_table[redir->rd_type].mode;
6065 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6066 openfd = open_or_warn(p, mode);
6067 free(p);
6068 if (openfd < 0) {
6069 /* this could get lost if stderr has been redirected, but
6070 * bash and ash both lose it as well (though zsh doesn't!) */
6071//what the above comment tries to say?
6072 return 1;
6073 }
6074 } else {
6075 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
6076 openfd = redir->rd_dup;
6077 }
6078
6079 if (openfd != redir->rd_fd) {
6080 if (squirrel && redir->rd_fd < 3
6081 && squirrel[redir->rd_fd] < 0
6082 ) {
6083 squirrel[redir->rd_fd] = dup(redir->rd_fd);
6084 }
6085 if (openfd == REDIRFD_CLOSE) {
6086 /* "n>-" means "close me" */
6087 close(redir->rd_fd);
6088 } else {
6089 xdup2(openfd, redir->rd_fd);
6090 if (redir->rd_dup == REDIRFD_TO_FILE)
6091 close(openfd);
6092 }
6093 }
6094 }
6095 return 0;
6096}
6097
6098static void restore_redirects(int squirrel[])
6099{
6100 int i, fd;
6101 for (i = 0; i < 3; i++) {
6102 fd = squirrel[i];
6103 if (fd != -1) {
6104 /* We simply die on error */
6105 xmove_fd(fd, i);
6106 }
6107 }
6108}
6109
6110static char *find_in_path(const char *arg)
6111{
6112 char *ret = NULL;
6113 const char *PATH = get_local_var_value("PATH");
6114
6115 if (!PATH)
6116 return NULL;
6117
6118 while (1) {
6119 const char *end = strchrnul(PATH, ':');
6120 int sz = end - PATH; /* must be int! */
6121
6122 free(ret);
6123 if (sz != 0) {
6124 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6125 } else {
6126 /* We have xxx::yyyy in $PATH,
6127 * it means "use current dir" */
6128 ret = xstrdup(arg);
6129 }
6130 if (access(ret, F_OK) == 0)
6131 break;
6132
6133 if (*end == '\0') {
6134 free(ret);
6135 return NULL;
6136 }
6137 PATH = end + 1;
6138 }
6139
6140 return ret;
6141}
6142
6143static const struct built_in_command *find_builtin_helper(const char *name,
6144 const struct built_in_command *x,
6145 const struct built_in_command *end)
6146{
6147 while (x != end) {
6148 if (strcmp(name, x->b_cmd) != 0) {
6149 x++;
6150 continue;
6151 }
6152 debug_printf_exec("found builtin '%s'\n", name);
6153 return x;
6154 }
6155 return NULL;
6156}
6157static const struct built_in_command *find_builtin1(const char *name)
6158{
6159 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6160}
6161static const struct built_in_command *find_builtin(const char *name)
6162{
6163 const struct built_in_command *x = find_builtin1(name);
6164 if (x)
6165 return x;
6166 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6167}
6168
6169#if ENABLE_HUSH_FUNCTIONS
6170static struct function **find_function_slot(const char *name)
6171{
6172 struct function **funcpp = &G.top_func;
6173 while (*funcpp) {
6174 if (strcmp(name, (*funcpp)->name) == 0) {
6175 break;
6176 }
6177 funcpp = &(*funcpp)->next;
6178 }
6179 return funcpp;
6180}
6181
6182static const struct function *find_function(const char *name)
6183{
6184 const struct function *funcp = *find_function_slot(name);
6185 if (funcp)
6186 debug_printf_exec("found function '%s'\n", name);
6187 return funcp;
6188}
6189
6190/* Note: takes ownership on name ptr */
6191static struct function *new_function(char *name)
6192{
6193 struct function **funcpp = find_function_slot(name);
6194 struct function *funcp = *funcpp;
6195
6196 if (funcp != NULL) {
6197 struct command *cmd = funcp->parent_cmd;
6198 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6199 if (!cmd) {
6200 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6201 free(funcp->name);
6202 /* Note: if !funcp->body, do not free body_as_string!
6203 * This is a special case of "-F name body" function:
6204 * body_as_string was not malloced! */
6205 if (funcp->body) {
6206 free_pipe_list(funcp->body);
6207# if !BB_MMU
6208 free(funcp->body_as_string);
6209# endif
6210 }
6211 } else {
6212 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6213 cmd->argv[0] = funcp->name;
6214 cmd->group = funcp->body;
6215# if !BB_MMU
6216 cmd->group_as_string = funcp->body_as_string;
6217# endif
6218 }
6219 } else {
6220 debug_printf_exec("remembering new function '%s'\n", name);
6221 funcp = *funcpp = xzalloc(sizeof(*funcp));
6222 /*funcp->next = NULL;*/
6223 }
6224
6225 funcp->name = name;
6226 return funcp;
6227}
6228
6229static void unset_func(const char *name)
6230{
6231 struct function **funcpp = find_function_slot(name);
6232 struct function *funcp = *funcpp;
6233
6234 if (funcp != NULL) {
6235 debug_printf_exec("freeing function '%s'\n", funcp->name);
6236 *funcpp = funcp->next;
6237 /* funcp is unlinked now, deleting it.
6238 * Note: if !funcp->body, the function was created by
6239 * "-F name body", do not free ->body_as_string
6240 * and ->name as they were not malloced. */
6241 if (funcp->body) {
6242 free_pipe_list(funcp->body);
6243 free(funcp->name);
6244# if !BB_MMU
6245 free(funcp->body_as_string);
6246# endif
6247 }
6248 free(funcp);
6249 }
6250}
6251
6252# if BB_MMU
6253#define exec_function(to_free, funcp, argv) \
6254 exec_function(funcp, argv)
6255# endif
6256static void exec_function(char ***to_free,
6257 const struct function *funcp,
6258 char **argv) NORETURN;
6259static void exec_function(char ***to_free,
6260 const struct function *funcp,
6261 char **argv)
6262{
6263# if BB_MMU
6264 int n = 1;
6265
6266 argv[0] = G.global_argv[0];
6267 G.global_argv = argv;
6268 while (*++argv)
6269 n++;
6270 G.global_argc = n;
6271 /* On MMU, funcp->body is always non-NULL */
6272 n = run_list(funcp->body);
6273 fflush_all();
6274 _exit(n);
6275# else
6276 re_execute_shell(to_free,
6277 funcp->body_as_string,
6278 G.global_argv[0],
6279 argv + 1,
6280 NULL);
6281# endif
6282}
6283
6284static int run_function(const struct function *funcp, char **argv)
6285{
6286 int rc;
6287 save_arg_t sv;
6288 smallint sv_flg;
6289
6290 save_and_replace_G_args(&sv, argv);
6291
6292 /* "we are in function, ok to use return" */
6293 sv_flg = G.flag_return_in_progress;
6294 G.flag_return_in_progress = -1;
6295# if ENABLE_HUSH_LOCAL
6296 G.func_nest_level++;
6297# endif
6298
6299 /* On MMU, funcp->body is always non-NULL */
6300# if !BB_MMU
6301 if (!funcp->body) {
6302 /* Function defined by -F */
6303 parse_and_run_string(funcp->body_as_string);
6304 rc = G.last_exitcode;
6305 } else
6306# endif
6307 {
6308 rc = run_list(funcp->body);
6309 }
6310
6311# if ENABLE_HUSH_LOCAL
6312 {
6313 struct variable *var;
6314 struct variable **var_pp;
6315
6316 var_pp = &G.top_var;
6317 while ((var = *var_pp) != NULL) {
6318 if (var->func_nest_level < G.func_nest_level) {
6319 var_pp = &var->next;
6320 continue;
6321 }
6322 /* Unexport */
6323 if (var->flg_export)
6324 bb_unsetenv(var->varstr);
6325 /* Remove from global list */
6326 *var_pp = var->next;
6327 /* Free */
6328 if (!var->max_len)
6329 free(var->varstr);
6330 free(var);
6331 }
6332 G.func_nest_level--;
6333 }
6334# endif
6335 G.flag_return_in_progress = sv_flg;
6336
6337 restore_G_args(&sv, argv);
6338
6339 return rc;
6340}
6341#endif /* ENABLE_HUSH_FUNCTIONS */
6342
6343
6344#if BB_MMU
6345#define exec_builtin(to_free, x, argv) \
6346 exec_builtin(x, argv)
6347#else
6348#define exec_builtin(to_free, x, argv) \
6349 exec_builtin(to_free, argv)
6350#endif
6351static void exec_builtin(char ***to_free,
6352 const struct built_in_command *x,
6353 char **argv) NORETURN;
6354static void exec_builtin(char ***to_free,
6355 const struct built_in_command *x,
6356 char **argv)
6357{
6358#if BB_MMU
6359 int rcode;
6360 fflush_all();
6361 rcode = x->b_function(argv);
6362 fflush_all();
6363 _exit(rcode);
6364#else
6365 fflush_all();
6366 /* On NOMMU, we must never block!
6367 * Example: { sleep 99 | read line; } & echo Ok
6368 */
6369 re_execute_shell(to_free,
6370 argv[0],
6371 G.global_argv[0],
6372 G.global_argv + 1,
6373 argv);
6374#endif
6375}
6376
6377
6378static void execvp_or_die(char **argv) NORETURN;
6379static void execvp_or_die(char **argv)
6380{
6381 debug_printf_exec("execing '%s'\n", argv[0]);
6382 /* Don't propagate SIG_IGN to the child */
6383 if (SPECIAL_JOBSTOP_SIGS != 0)
6384 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6385 execvp(argv[0], argv);
6386 bb_perror_msg("can't execute '%s'", argv[0]);
6387 _exit(127); /* bash compat */
6388}
6389
6390#if ENABLE_HUSH_MODE_X
6391static void dump_cmd_in_x_mode(char **argv)
6392{
6393 if (G_x_mode && argv) {
6394 /* We want to output the line in one write op */
6395 char *buf, *p;
6396 int len;
6397 int n;
6398
6399 len = 3;
6400 n = 0;
6401 while (argv[n])
6402 len += strlen(argv[n++]) + 1;
6403 buf = xmalloc(len);
6404 buf[0] = '+';
6405 p = buf + 1;
6406 n = 0;
6407 while (argv[n])
6408 p += sprintf(p, " %s", argv[n++]);
6409 *p++ = '\n';
6410 *p = '\0';
6411 fputs(buf, stderr);
6412 free(buf);
6413 }
6414}
6415#else
6416# define dump_cmd_in_x_mode(argv) ((void)0)
6417#endif
6418
6419#if BB_MMU
6420#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6421 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6422#define pseudo_exec(nommu_save, command, argv_expanded) \
6423 pseudo_exec(command, argv_expanded)
6424#endif
6425
6426/* Called after [v]fork() in run_pipe, or from builtin_exec.
6427 * Never returns.
6428 * Don't exit() here. If you don't exec, use _exit instead.
6429 * The at_exit handlers apparently confuse the calling process,
6430 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
6431static void pseudo_exec_argv(nommu_save_t *nommu_save,
6432 char **argv, int assignment_cnt,
6433 char **argv_expanded) NORETURN;
6434static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6435 char **argv, int assignment_cnt,
6436 char **argv_expanded)
6437{
6438 char **new_env;
6439
6440 new_env = expand_assignments(argv, assignment_cnt);
6441 dump_cmd_in_x_mode(new_env);
6442
6443 if (!argv[assignment_cnt]) {
6444 /* Case when we are here: ... | var=val | ...
6445 * (note that we do not exit early, i.e., do not optimize out
6446 * expand_assignments(): think about ... | var=`sleep 1` | ...
6447 */
6448 free_strings(new_env);
6449 _exit(EXIT_SUCCESS);
6450 }
6451
6452#if BB_MMU
6453 set_vars_and_save_old(new_env);
6454 free(new_env); /* optional */
6455 /* we can also destroy set_vars_and_save_old's return value,
6456 * to save memory */
6457#else
6458 nommu_save->new_env = new_env;
6459 nommu_save->old_vars = set_vars_and_save_old(new_env);
6460#endif
6461
6462 if (argv_expanded) {
6463 argv = argv_expanded;
6464 } else {
6465 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6466#if !BB_MMU
6467 nommu_save->argv = argv;
6468#endif
6469 }
6470 dump_cmd_in_x_mode(argv);
6471
6472#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6473 if (strchr(argv[0], '/') != NULL)
6474 goto skip;
6475#endif
6476
6477 /* Check if the command matches any of the builtins.
6478 * Depending on context, this might be redundant. But it's
6479 * easier to waste a few CPU cycles than it is to figure out
6480 * if this is one of those cases.
6481 */
6482 {
6483 /* On NOMMU, it is more expensive to re-execute shell
6484 * just in order to run echo or test builtin.
6485 * It's better to skip it here and run corresponding
6486 * non-builtin later. */
6487 const struct built_in_command *x;
6488 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6489 if (x) {
6490 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6491 }
6492 }
6493#if ENABLE_HUSH_FUNCTIONS
6494 /* Check if the command matches any functions */
6495 {
6496 const struct function *funcp = find_function(argv[0]);
6497 if (funcp) {
6498 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6499 }
6500 }
6501#endif
6502
6503#if ENABLE_FEATURE_SH_STANDALONE
6504 /* Check if the command matches any busybox applets */
6505 {
6506 int a = find_applet_by_name(argv[0]);
6507 if (a >= 0) {
6508# if BB_MMU /* see above why on NOMMU it is not allowed */
6509 if (APPLET_IS_NOEXEC(a)) {
6510 debug_printf_exec("running applet '%s'\n", argv[0]);
6511 run_applet_no_and_exit(a, argv);
6512 }
6513# endif
6514 /* Re-exec ourselves */
6515 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6516 /* Don't propagate SIG_IGN to the child */
6517 if (SPECIAL_JOBSTOP_SIGS != 0)
6518 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6519 execv(bb_busybox_exec_path, argv);
6520 /* If they called chroot or otherwise made the binary no longer
6521 * executable, fall through */
6522 }
6523 }
6524#endif
6525
6526#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6527 skip:
6528#endif
6529 execvp_or_die(argv);
6530}
6531
6532/* Called after [v]fork() in run_pipe
6533 */
6534static void pseudo_exec(nommu_save_t *nommu_save,
6535 struct command *command,
6536 char **argv_expanded) NORETURN;
6537static void pseudo_exec(nommu_save_t *nommu_save,
6538 struct command *command,
6539 char **argv_expanded)
6540{
6541 if (command->argv) {
6542 pseudo_exec_argv(nommu_save, command->argv,
6543 command->assignment_cnt, argv_expanded);
6544 }
6545
6546 if (command->group) {
6547 /* Cases when we are here:
6548 * ( list )
6549 * { list } &
6550 * ... | ( list ) | ...
6551 * ... | { list } | ...
6552 */
6553#if BB_MMU
6554 int rcode;
6555 debug_printf_exec("pseudo_exec: run_list\n");
6556 reset_traps_to_defaults();
6557 rcode = run_list(command->group);
6558 /* OK to leak memory by not calling free_pipe_list,
6559 * since this process is about to exit */
6560 _exit(rcode);
6561#else
6562 re_execute_shell(&nommu_save->argv_from_re_execing,
6563 command->group_as_string,
6564 G.global_argv[0],
6565 G.global_argv + 1,
6566 NULL);
6567#endif
6568 }
6569
6570 /* Case when we are here: ... | >file */
6571 debug_printf_exec("pseudo_exec'ed null command\n");
6572 _exit(EXIT_SUCCESS);
6573}
6574
6575#if ENABLE_HUSH_JOB
6576static const char *get_cmdtext(struct pipe *pi)
6577{
6578 char **argv;
6579 char *p;
6580 int len;
6581
6582 /* This is subtle. ->cmdtext is created only on first backgrounding.
6583 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6584 * On subsequent bg argv is trashed, but we won't use it */
6585 if (pi->cmdtext)
6586 return pi->cmdtext;
6587 argv = pi->cmds[0].argv;
6588 if (!argv || !argv[0]) {
6589 pi->cmdtext = xzalloc(1);
6590 return pi->cmdtext;
6591 }
6592
6593 len = 0;
6594 do {
6595 len += strlen(*argv) + 1;
6596 } while (*++argv);
6597 p = xmalloc(len);
6598 pi->cmdtext = p;
6599 argv = pi->cmds[0].argv;
6600 do {
6601 len = strlen(*argv);
6602 memcpy(p, *argv, len);
6603 p += len;
6604 *p++ = ' ';
6605 } while (*++argv);
6606 p[-1] = '\0';
6607 return pi->cmdtext;
6608}
6609
6610static void insert_bg_job(struct pipe *pi)
6611{
6612 struct pipe *job, **jobp;
6613 int i;
6614
6615 /* Linear search for the ID of the job to use */
6616 pi->jobid = 1;
6617 for (job = G.job_list; job; job = job->next)
6618 if (job->jobid >= pi->jobid)
6619 pi->jobid = job->jobid + 1;
6620
6621 /* Add job to the list of running jobs */
6622 jobp = &G.job_list;
6623 while ((job = *jobp) != NULL)
6624 jobp = &job->next;
6625 job = *jobp = xmalloc(sizeof(*job));
6626
6627 *job = *pi; /* physical copy */
6628 job->next = NULL;
6629 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6630 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6631 for (i = 0; i < pi->num_cmds; i++) {
6632 job->cmds[i].pid = pi->cmds[i].pid;
6633 /* all other fields are not used and stay zero */
6634 }
6635 job->cmdtext = xstrdup(get_cmdtext(pi));
6636
6637 if (G_interactive_fd)
6638 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6639 G.last_jobid = job->jobid;
6640}
6641
6642static void remove_bg_job(struct pipe *pi)
6643{
6644 struct pipe *prev_pipe;
6645
6646 if (pi == G.job_list) {
6647 G.job_list = pi->next;
6648 } else {
6649 prev_pipe = G.job_list;
6650 while (prev_pipe->next != pi)
6651 prev_pipe = prev_pipe->next;
6652 prev_pipe->next = pi->next;
6653 }
6654 if (G.job_list)
6655 G.last_jobid = G.job_list->jobid;
6656 else
6657 G.last_jobid = 0;
6658}
6659
6660/* Remove a backgrounded job */
6661static void delete_finished_bg_job(struct pipe *pi)
6662{
6663 remove_bg_job(pi);
6664 free_pipe(pi);
6665}
6666#endif /* JOB */
6667
6668/* Check to see if any processes have exited -- if they
6669 * have, figure out why and see if a job has completed */
6670static int checkjobs(struct pipe *fg_pipe)
6671{
6672 int attributes;
6673 int status;
6674#if ENABLE_HUSH_JOB
6675 struct pipe *pi;
6676#endif
6677 pid_t childpid;
6678 int rcode = 0;
6679
6680 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6681
6682 attributes = WUNTRACED;
6683 if (fg_pipe == NULL)
6684 attributes |= WNOHANG;
6685
6686 errno = 0;
6687#if ENABLE_HUSH_FAST
6688 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6689//bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6690//getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6691 /* There was neither fork nor SIGCHLD since last waitpid */
6692 /* Avoid doing waitpid syscall if possible */
6693 if (!G.we_have_children) {
6694 errno = ECHILD;
6695 return -1;
6696 }
6697 if (fg_pipe == NULL) { /* is WNOHANG set? */
6698 /* We have children, but they did not exit
6699 * or stop yet (we saw no SIGCHLD) */
6700 return 0;
6701 }
6702 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6703 }
6704#endif
6705
6706/* Do we do this right?
6707 * bash-3.00# sleep 20 | false
6708 * <ctrl-Z pressed>
6709 * [3]+ Stopped sleep 20 | false
6710 * bash-3.00# echo $?
6711 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6712 * [hush 1.14.0: yes we do it right]
6713 */
6714 wait_more:
6715 while (1) {
6716 int i;
6717 int dead;
6718
6719#if ENABLE_HUSH_FAST
6720 i = G.count_SIGCHLD;
6721#endif
6722 childpid = waitpid(-1, &status, attributes);
6723 if (childpid <= 0) {
6724 if (childpid && errno != ECHILD)
6725 bb_perror_msg("waitpid");
6726#if ENABLE_HUSH_FAST
6727 else { /* Until next SIGCHLD, waitpid's are useless */
6728 G.we_have_children = (childpid == 0);
6729 G.handled_SIGCHLD = i;
6730//bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6731 }
6732#endif
6733 break;
6734 }
6735 dead = WIFEXITED(status) || WIFSIGNALED(status);
6736
6737#if DEBUG_JOBS
6738 if (WIFSTOPPED(status))
6739 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6740 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6741 if (WIFSIGNALED(status))
6742 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6743 childpid, WTERMSIG(status), WEXITSTATUS(status));
6744 if (WIFEXITED(status))
6745 debug_printf_jobs("pid %d exited, exitcode %d\n",
6746 childpid, WEXITSTATUS(status));
6747#endif
6748 /* Were we asked to wait for fg pipe? */
6749 if (fg_pipe) {
6750 i = fg_pipe->num_cmds;
6751 while (--i >= 0) {
6752 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6753 if (fg_pipe->cmds[i].pid != childpid)
6754 continue;
6755 if (dead) {
6756 int ex;
6757 fg_pipe->cmds[i].pid = 0;
6758 fg_pipe->alive_cmds--;
6759 ex = WEXITSTATUS(status);
6760 /* bash prints killer signal's name for *last*
6761 * process in pipe (prints just newline for SIGINT/SIGPIPE).
6762 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6763 */
6764 if (WIFSIGNALED(status)) {
6765 int sig = WTERMSIG(status);
6766 if (i == fg_pipe->num_cmds-1)
6767 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
6768 printf("%s\n", sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
6769 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
6770 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6771 * Maybe we need to use sig | 128? */
6772 ex = sig + 128;
6773 }
6774 fg_pipe->cmds[i].cmd_exitcode = ex;
6775 } else {
6776 fg_pipe->stopped_cmds++;
6777 }
6778 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6779 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6780 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
6781 /* All processes in fg pipe have exited or stopped */
6782 i = fg_pipe->num_cmds;
6783 while (--i >= 0) {
6784 rcode = fg_pipe->cmds[i].cmd_exitcode;
6785 /* usually last process gives overall exitstatus,
6786 * but with "set -o pipefail", last *failed* process does */
6787 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
6788 break;
6789 }
6790 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6791/* Note: *non-interactive* bash does not continue if all processes in fg pipe
6792 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6793 * and "killall -STOP cat" */
6794 if (G_interactive_fd) {
6795#if ENABLE_HUSH_JOB
6796 if (fg_pipe->alive_cmds != 0)
6797 insert_bg_job(fg_pipe);
6798#endif
6799 return rcode;
6800 }
6801 if (fg_pipe->alive_cmds == 0)
6802 return rcode;
6803 }
6804 /* There are still running processes in the fg pipe */
6805 goto wait_more; /* do waitpid again */
6806 }
6807 /* it wasnt fg_pipe, look for process in bg pipes */
6808 }
6809
6810#if ENABLE_HUSH_JOB
6811 /* We asked to wait for bg or orphaned children */
6812 /* No need to remember exitcode in this case */
6813 for (pi = G.job_list; pi; pi = pi->next) {
6814 for (i = 0; i < pi->num_cmds; i++) {
6815 if (pi->cmds[i].pid == childpid)
6816 goto found_pi_and_prognum;
6817 }
6818 }
6819 /* Happens when shell is used as init process (init=/bin/sh) */
6820 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6821 continue; /* do waitpid again */
6822
6823 found_pi_and_prognum:
6824 if (dead) {
6825 /* child exited */
6826 pi->cmds[i].pid = 0;
6827 pi->alive_cmds--;
6828 if (!pi->alive_cmds) {
6829 if (G_interactive_fd)
6830 printf(JOB_STATUS_FORMAT, pi->jobid,
6831 "Done", pi->cmdtext);
6832 delete_finished_bg_job(pi);
6833 }
6834 } else {
6835 /* child stopped */
6836 pi->stopped_cmds++;
6837 }
6838#endif
6839 } /* while (waitpid succeeds)... */
6840
6841 return rcode;
6842}
6843
6844#if ENABLE_HUSH_JOB
6845static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6846{
6847 pid_t p;
6848 int rcode = checkjobs(fg_pipe);
6849 if (G_saved_tty_pgrp) {
6850 /* Job finished, move the shell to the foreground */
6851 p = getpgrp(); /* our process group id */
6852 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6853 tcsetpgrp(G_interactive_fd, p);
6854 }
6855 return rcode;
6856}
6857#endif
6858
6859/* Start all the jobs, but don't wait for anything to finish.
6860 * See checkjobs().
6861 *
6862 * Return code is normally -1, when the caller has to wait for children
6863 * to finish to determine the exit status of the pipe. If the pipe
6864 * is a simple builtin command, however, the action is done by the
6865 * time run_pipe returns, and the exit code is provided as the
6866 * return value.
6867 *
6868 * Returns -1 only if started some children. IOW: we have to
6869 * mask out retvals of builtins etc with 0xff!
6870 *
6871 * The only case when we do not need to [v]fork is when the pipe
6872 * is single, non-backgrounded, non-subshell command. Examples:
6873 * cmd ; ... { list } ; ...
6874 * cmd && ... { list } && ...
6875 * cmd || ... { list } || ...
6876 * If it is, then we can run cmd as a builtin, NOFORK,
6877 * or (if SH_STANDALONE) an applet, and we can run the { list }
6878 * with run_list. If it isn't one of these, we fork and exec cmd.
6879 *
6880 * Cases when we must fork:
6881 * non-single: cmd | cmd
6882 * backgrounded: cmd & { list } &
6883 * subshell: ( list ) [&]
6884 */
6885#if !ENABLE_HUSH_MODE_X
6886#define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
6887 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6888#endif
6889static int redirect_and_varexp_helper(char ***new_env_p,
6890 struct variable **old_vars_p,
6891 struct command *command,
6892 int squirrel[3],
6893 char **argv_expanded)
6894{
6895 /* setup_redirects acts on file descriptors, not FILEs.
6896 * This is perfect for work that comes after exec().
6897 * Is it really safe for inline use? Experimentally,
6898 * things seem to work. */
6899 int rcode = setup_redirects(command, squirrel);
6900 if (rcode == 0) {
6901 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6902 *new_env_p = new_env;
6903 dump_cmd_in_x_mode(new_env);
6904 dump_cmd_in_x_mode(argv_expanded);
6905 if (old_vars_p)
6906 *old_vars_p = set_vars_and_save_old(new_env);
6907 }
6908 return rcode;
6909}
6910static NOINLINE int run_pipe(struct pipe *pi)
6911{
6912 static const char *const null_ptr = NULL;
6913
6914 int cmd_no;
6915 int next_infd;
6916 struct command *command;
6917 char **argv_expanded;
6918 char **argv;
6919 /* it is not always needed, but we aim to smaller code */
6920 int squirrel[] = { -1, -1, -1 };
6921 int rcode;
6922
6923 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6924 debug_enter();
6925
6926 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6927 * Result should be 3 lines: q w e, qwe, q w e
6928 */
6929 G.ifs = get_local_var_value("IFS");
6930 if (!G.ifs)
6931 G.ifs = defifs;
6932
6933 IF_HUSH_JOB(pi->pgrp = -1;)
6934 pi->stopped_cmds = 0;
6935 command = &pi->cmds[0];
6936 argv_expanded = NULL;
6937
6938 if (pi->num_cmds != 1
6939 || pi->followup == PIPE_BG
6940 || command->cmd_type == CMD_SUBSHELL
6941 ) {
6942 goto must_fork;
6943 }
6944
6945 pi->alive_cmds = 1;
6946
6947 debug_printf_exec(": group:%p argv:'%s'\n",
6948 command->group, command->argv ? command->argv[0] : "NONE");
6949
6950 if (command->group) {
6951#if ENABLE_HUSH_FUNCTIONS
6952 if (command->cmd_type == CMD_FUNCDEF) {
6953 /* "executing" func () { list } */
6954 struct function *funcp;
6955
6956 funcp = new_function(command->argv[0]);
6957 /* funcp->name is already set to argv[0] */
6958 funcp->body = command->group;
6959# if !BB_MMU
6960 funcp->body_as_string = command->group_as_string;
6961 command->group_as_string = NULL;
6962# endif
6963 command->group = NULL;
6964 command->argv[0] = NULL;
6965 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6966 funcp->parent_cmd = command;
6967 command->child_func = funcp;
6968
6969 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6970 debug_leave();
6971 return EXIT_SUCCESS;
6972 }
6973#endif
6974 /* { list } */
6975 debug_printf("non-subshell group\n");
6976 rcode = 1; /* exitcode if redir failed */
6977 if (setup_redirects(command, squirrel) == 0) {
6978 debug_printf_exec(": run_list\n");
6979 rcode = run_list(command->group) & 0xff;
6980 }
6981 restore_redirects(squirrel);
6982 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6983 debug_leave();
6984 debug_printf_exec("run_pipe: return %d\n", rcode);
6985 return rcode;
6986 }
6987
6988 argv = command->argv ? command->argv : (char **) &null_ptr;
6989 {
6990 const struct built_in_command *x;
6991#if ENABLE_HUSH_FUNCTIONS
6992 const struct function *funcp;
6993#else
6994 enum { funcp = 0 };
6995#endif
6996 char **new_env = NULL;
6997 struct variable *old_vars = NULL;
6998
6999 if (argv[command->assignment_cnt] == NULL) {
7000 /* Assignments, but no command */
7001 /* Ensure redirects take effect (that is, create files).
7002 * Try "a=t >file" */
7003#if 0 /* A few cases in testsuite fail with this code. FIXME */
7004 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7005 /* Set shell variables */
7006 if (new_env) {
7007 argv = new_env;
7008 while (*argv) {
7009 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7010 /* Do we need to flag set_local_var() errors?
7011 * "assignment to readonly var" and "putenv error"
7012 */
7013 argv++;
7014 }
7015 }
7016 /* Redirect error sets $? to 1. Otherwise,
7017 * if evaluating assignment value set $?, retain it.
7018 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7019 if (rcode == 0)
7020 rcode = G.last_exitcode;
7021 /* Exit, _skipping_ variable restoring code: */
7022 goto clean_up_and_ret0;
7023
7024#else /* Older, bigger, but more correct code */
7025
7026 rcode = setup_redirects(command, squirrel);
7027 restore_redirects(squirrel);
7028 /* Set shell variables */
7029 if (G_x_mode)
7030 bb_putchar_stderr('+');
7031 while (*argv) {
7032 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7033 if (G_x_mode)
7034 fprintf(stderr, " %s", p);
7035 debug_printf_exec("set shell var:'%s'->'%s'\n",
7036 *argv, p);
7037 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7038 /* Do we need to flag set_local_var() errors?
7039 * "assignment to readonly var" and "putenv error"
7040 */
7041 argv++;
7042 }
7043 if (G_x_mode)
7044 bb_putchar_stderr('\n');
7045 /* Redirect error sets $? to 1. Otherwise,
7046 * if evaluating assignment value set $?, retain it.
7047 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7048 if (rcode == 0)
7049 rcode = G.last_exitcode;
7050 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7051 debug_leave();
7052 debug_printf_exec("run_pipe: return %d\n", rcode);
7053 return rcode;
7054#endif
7055 }
7056
7057 /* Expand the rest into (possibly) many strings each */
7058#if ENABLE_HUSH_BASH_COMPAT
7059 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7060 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7061 } else
7062#endif
7063 {
7064 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7065 }
7066
7067 /* if someone gives us an empty string: `cmd with empty output` */
7068 if (!argv_expanded[0]) {
7069 free(argv_expanded);
7070 debug_leave();
7071 return G.last_exitcode;
7072 }
7073
7074 x = find_builtin(argv_expanded[0]);
7075#if ENABLE_HUSH_FUNCTIONS
7076 funcp = NULL;
7077 if (!x)
7078 funcp = find_function(argv_expanded[0]);
7079#endif
7080 if (x || funcp) {
7081 if (!funcp) {
7082 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7083 debug_printf("exec with redirects only\n");
7084 rcode = setup_redirects(command, NULL);
7085 goto clean_up_and_ret1;
7086 }
7087 }
7088 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7089 if (rcode == 0) {
7090 if (!funcp) {
7091 debug_printf_exec(": builtin '%s' '%s'...\n",
7092 x->b_cmd, argv_expanded[1]);
7093 fflush_all();
7094 rcode = x->b_function(argv_expanded) & 0xff;
7095 fflush_all();
7096 }
7097#if ENABLE_HUSH_FUNCTIONS
7098 else {
7099# if ENABLE_HUSH_LOCAL
7100 struct variable **sv;
7101 sv = G.shadowed_vars_pp;
7102 G.shadowed_vars_pp = &old_vars;
7103# endif
7104 debug_printf_exec(": function '%s' '%s'...\n",
7105 funcp->name, argv_expanded[1]);
7106 rcode = run_function(funcp, argv_expanded) & 0xff;
7107# if ENABLE_HUSH_LOCAL
7108 G.shadowed_vars_pp = sv;
7109# endif
7110 }
7111#endif
7112 }
7113 clean_up_and_ret:
7114 unset_vars(new_env);
7115 add_vars(old_vars);
7116/* clean_up_and_ret0: */
7117 restore_redirects(squirrel);
7118 clean_up_and_ret1:
7119 free(argv_expanded);
7120 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7121 debug_leave();
7122 debug_printf_exec("run_pipe return %d\n", rcode);
7123 return rcode;
7124 }
7125
7126 if (ENABLE_FEATURE_SH_NOFORK) {
7127 int n = find_applet_by_name(argv_expanded[0]);
7128 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7129 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7130 if (rcode == 0) {
7131 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7132 argv_expanded[0], argv_expanded[1]);
7133 rcode = run_nofork_applet(n, argv_expanded);
7134 }
7135 goto clean_up_and_ret;
7136 }
7137 }
7138 /* It is neither builtin nor applet. We must fork. */
7139 }
7140
7141 must_fork:
7142 /* NB: argv_expanded may already be created, and that
7143 * might include `cmd` runs! Do not rerun it! We *must*
7144 * use argv_expanded if it's non-NULL */
7145
7146 /* Going to fork a child per each pipe member */
7147 pi->alive_cmds = 0;
7148 next_infd = 0;
7149
7150 cmd_no = 0;
7151 while (cmd_no < pi->num_cmds) {
7152 struct fd_pair pipefds;
7153#if !BB_MMU
7154 volatile nommu_save_t nommu_save;
7155 nommu_save.new_env = NULL;
7156 nommu_save.old_vars = NULL;
7157 nommu_save.argv = NULL;
7158 nommu_save.argv_from_re_execing = NULL;
7159#endif
7160 command = &pi->cmds[cmd_no];
7161 cmd_no++;
7162 if (command->argv) {
7163 debug_printf_exec(": pipe member '%s' '%s'...\n",
7164 command->argv[0], command->argv[1]);
7165 } else {
7166 debug_printf_exec(": pipe member with no argv\n");
7167 }
7168
7169 /* pipes are inserted between pairs of commands */
7170 pipefds.rd = 0;
7171 pipefds.wr = 1;
7172 if (cmd_no < pi->num_cmds)
7173 xpiped_pair(pipefds);
7174
7175 command->pid = BB_MMU ? fork() : vfork();
7176 if (!command->pid) { /* child */
7177#if ENABLE_HUSH_JOB
7178 disable_restore_tty_pgrp_on_exit();
7179 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7180
7181 /* Every child adds itself to new process group
7182 * with pgid == pid_of_first_child_in_pipe */
7183 if (G.run_list_level == 1 && G_interactive_fd) {
7184 pid_t pgrp;
7185 pgrp = pi->pgrp;
7186 if (pgrp < 0) /* true for 1st process only */
7187 pgrp = getpid();
7188 if (setpgid(0, pgrp) == 0
7189 && pi->followup != PIPE_BG
7190 && G_saved_tty_pgrp /* we have ctty */
7191 ) {
7192 /* We do it in *every* child, not just first,
7193 * to avoid races */
7194 tcsetpgrp(G_interactive_fd, pgrp);
7195 }
7196 }
7197#endif
7198 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7199 /* 1st cmd in backgrounded pipe
7200 * should have its stdin /dev/null'ed */
7201 close(0);
7202 if (open(bb_dev_null, O_RDONLY))
7203 xopen("/", O_RDONLY);
7204 } else {
7205 xmove_fd(next_infd, 0);
7206 }
7207 xmove_fd(pipefds.wr, 1);
7208 if (pipefds.rd > 1)
7209 close(pipefds.rd);
7210 /* Like bash, explicit redirects override pipes,
7211 * and the pipe fd is available for dup'ing. */
7212 if (setup_redirects(command, NULL))
7213 _exit(1);
7214
7215 /* Stores to nommu_save list of env vars putenv'ed
7216 * (NOMMU, on MMU we don't need that) */
7217 /* cast away volatility... */
7218 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7219 /* pseudo_exec() does not return */
7220 }
7221
7222 /* parent or error */
7223#if ENABLE_HUSH_FAST
7224 G.count_SIGCHLD++;
7225//bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7226#endif
7227 enable_restore_tty_pgrp_on_exit();
7228#if !BB_MMU
7229 /* Clean up after vforked child */
7230 free(nommu_save.argv);
7231 free(nommu_save.argv_from_re_execing);
7232 unset_vars(nommu_save.new_env);
7233 add_vars(nommu_save.old_vars);
7234#endif
7235 free(argv_expanded);
7236 argv_expanded = NULL;
7237 if (command->pid < 0) { /* [v]fork failed */
7238 /* Clearly indicate, was it fork or vfork */
7239 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7240 } else {
7241 pi->alive_cmds++;
7242#if ENABLE_HUSH_JOB
7243 /* Second and next children need to know pid of first one */
7244 if (pi->pgrp < 0)
7245 pi->pgrp = command->pid;
7246#endif
7247 }
7248
7249 if (cmd_no > 1)
7250 close(next_infd);
7251 if (cmd_no < pi->num_cmds)
7252 close(pipefds.wr);
7253 /* Pass read (output) pipe end to next iteration */
7254 next_infd = pipefds.rd;
7255 }
7256
7257 if (!pi->alive_cmds) {
7258 debug_leave();
7259 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7260 return 1;
7261 }
7262
7263 debug_leave();
7264 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7265 return -1;
7266}
7267
7268/* NB: called by pseudo_exec, and therefore must not modify any
7269 * global data until exec/_exit (we can be a child after vfork!) */
7270static int run_list(struct pipe *pi)
7271{
7272#if ENABLE_HUSH_CASE
7273 char *case_word = NULL;
7274#endif
7275#if ENABLE_HUSH_LOOPS
7276 struct pipe *loop_top = NULL;
7277 char **for_lcur = NULL;
7278 char **for_list = NULL;
7279#endif
7280 smallint last_followup;
7281 smalluint rcode;
7282#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7283 smalluint cond_code = 0;
7284#else
7285 enum { cond_code = 0 };
7286#endif
7287#if HAS_KEYWORDS
7288 smallint rword; /* RES_foo */
7289 smallint last_rword; /* ditto */
7290#endif
7291
7292 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7293 debug_enter();
7294
7295#if ENABLE_HUSH_LOOPS
7296 /* Check syntax for "for" */
7297 {
7298 struct pipe *cpipe;
7299 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7300 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7301 continue;
7302 /* current word is FOR or IN (BOLD in comments below) */
7303 if (cpipe->next == NULL) {
7304 syntax_error("malformed for");
7305 debug_leave();
7306 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7307 return 1;
7308 }
7309 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7310 if (cpipe->next->res_word == RES_DO)
7311 continue;
7312 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7313 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7314 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7315 ) {
7316 syntax_error("malformed for");
7317 debug_leave();
7318 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7319 return 1;
7320 }
7321 }
7322 }
7323#endif
7324
7325 /* Past this point, all code paths should jump to ret: label
7326 * in order to return, no direct "return" statements please.
7327 * This helps to ensure that no memory is leaked. */
7328
7329#if ENABLE_HUSH_JOB
7330 G.run_list_level++;
7331#endif
7332
7333#if HAS_KEYWORDS
7334 rword = RES_NONE;
7335 last_rword = RES_XXXX;
7336#endif
7337 last_followup = PIPE_SEQ;
7338 rcode = G.last_exitcode;
7339
7340 /* Go through list of pipes, (maybe) executing them. */
7341 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7342 if (G.flag_SIGINT)
7343 break;
7344
7345 IF_HAS_KEYWORDS(rword = pi->res_word;)
7346 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7347 rword, cond_code, last_rword);
7348#if ENABLE_HUSH_LOOPS
7349 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7350 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7351 ) {
7352 /* start of a loop: remember where loop starts */
7353 loop_top = pi;
7354 G.depth_of_loop++;
7355 }
7356#endif
7357 /* Still in the same "if...", "then..." or "do..." branch? */
7358 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7359 if ((rcode == 0 && last_followup == PIPE_OR)
7360 || (rcode != 0 && last_followup == PIPE_AND)
7361 ) {
7362 /* It is "<true> || CMD" or "<false> && CMD"
7363 * and we should not execute CMD */
7364 debug_printf_exec("skipped cmd because of || or &&\n");
7365 last_followup = pi->followup;
7366 goto dont_check_jobs_but_continue;
7367 }
7368 }
7369 last_followup = pi->followup;
7370 IF_HAS_KEYWORDS(last_rword = rword;)
7371#if ENABLE_HUSH_IF
7372 if (cond_code) {
7373 if (rword == RES_THEN) {
7374 /* if false; then ... fi has exitcode 0! */
7375 G.last_exitcode = rcode = EXIT_SUCCESS;
7376 /* "if <false> THEN cmd": skip cmd */
7377 continue;
7378 }
7379 } else {
7380 if (rword == RES_ELSE || rword == RES_ELIF) {
7381 /* "if <true> then ... ELSE/ELIF cmd":
7382 * skip cmd and all following ones */
7383 break;
7384 }
7385 }
7386#endif
7387#if ENABLE_HUSH_LOOPS
7388 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7389 if (!for_lcur) {
7390 /* first loop through for */
7391
7392 static const char encoded_dollar_at[] ALIGN1 = {
7393 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7394 }; /* encoded representation of "$@" */
7395 static const char *const encoded_dollar_at_argv[] = {
7396 encoded_dollar_at, NULL
7397 }; /* argv list with one element: "$@" */
7398 char **vals;
7399
7400 vals = (char**)encoded_dollar_at_argv;
7401 if (pi->next->res_word == RES_IN) {
7402 /* if no variable values after "in" we skip "for" */
7403 if (!pi->next->cmds[0].argv) {
7404 G.last_exitcode = rcode = EXIT_SUCCESS;
7405 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7406 break;
7407 }
7408 vals = pi->next->cmds[0].argv;
7409 } /* else: "for var; do..." -> assume "$@" list */
7410 /* create list of variable values */
7411 debug_print_strings("for_list made from", vals);
7412 for_list = expand_strvec_to_strvec(vals);
7413 for_lcur = for_list;
7414 debug_print_strings("for_list", for_list);
7415 }
7416 if (!*for_lcur) {
7417 /* "for" loop is over, clean up */
7418 free(for_list);
7419 for_list = NULL;
7420 for_lcur = NULL;
7421 break;
7422 }
7423 /* Insert next value from for_lcur */
7424 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7425 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7426 continue;
7427 }
7428 if (rword == RES_IN) {
7429 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7430 }
7431 if (rword == RES_DONE) {
7432 continue; /* "done" has no cmds too */
7433 }
7434#endif
7435#if ENABLE_HUSH_CASE
7436 if (rword == RES_CASE) {
7437 case_word = expand_strvec_to_string(pi->cmds->argv);
7438 continue;
7439 }
7440 if (rword == RES_MATCH) {
7441 char **argv;
7442
7443 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7444 break;
7445 /* all prev words didn't match, does this one match? */
7446 argv = pi->cmds->argv;
7447 while (*argv) {
7448 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7449 /* TODO: which FNM_xxx flags to use? */
7450 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7451 free(pattern);
7452 if (cond_code == 0) { /* match! we will execute this branch */
7453 free(case_word); /* make future "word)" stop */
7454 case_word = NULL;
7455 break;
7456 }
7457 argv++;
7458 }
7459 continue;
7460 }
7461 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7462 if (cond_code != 0)
7463 continue; /* not matched yet, skip this pipe */
7464 }
7465#endif
7466 /* Just pressing <enter> in shell should check for jobs.
7467 * OTOH, in non-interactive shell this is useless
7468 * and only leads to extra job checks */
7469 if (pi->num_cmds == 0) {
7470 if (G_interactive_fd)
7471 goto check_jobs_and_continue;
7472 continue;
7473 }
7474
7475 /* After analyzing all keywords and conditions, we decided
7476 * to execute this pipe. NB: have to do checkjobs(NULL)
7477 * after run_pipe to collect any background children,
7478 * even if list execution is to be stopped. */
7479 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7480 {
7481 int r;
7482#if ENABLE_HUSH_LOOPS
7483 G.flag_break_continue = 0;
7484#endif
7485 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7486 if (r != -1) {
7487 /* We ran a builtin, function, or group.
7488 * rcode is already known
7489 * and we don't need to wait for anything. */
7490 G.last_exitcode = rcode;
7491 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7492 check_and_run_traps();
7493#if ENABLE_HUSH_LOOPS
7494 /* Was it "break" or "continue"? */
7495 if (G.flag_break_continue) {
7496 smallint fbc = G.flag_break_continue;
7497 /* We might fall into outer *loop*,
7498 * don't want to break it too */
7499 if (loop_top) {
7500 G.depth_break_continue--;
7501 if (G.depth_break_continue == 0)
7502 G.flag_break_continue = 0;
7503 /* else: e.g. "continue 2" should *break* once, *then* continue */
7504 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7505 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7506 checkjobs(NULL);
7507 break;
7508 }
7509 /* "continue": simulate end of loop */
7510 rword = RES_DONE;
7511 continue;
7512 }
7513#endif
7514#if ENABLE_HUSH_FUNCTIONS
7515 if (G.flag_return_in_progress == 1) {
7516 checkjobs(NULL);
7517 break;
7518 }
7519#endif
7520 } else if (pi->followup == PIPE_BG) {
7521 /* What does bash do with attempts to background builtins? */
7522 /* even bash 3.2 doesn't do that well with nested bg:
7523 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7524 * I'm NOT treating inner &'s as jobs */
7525 check_and_run_traps();
7526#if ENABLE_HUSH_JOB
7527 if (G.run_list_level == 1)
7528 insert_bg_job(pi);
7529#endif
7530 /* Last command's pid goes to $! */
7531 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7532 G.last_exitcode = rcode = EXIT_SUCCESS;
7533 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7534 } else {
7535#if ENABLE_HUSH_JOB
7536 if (G.run_list_level == 1 && G_interactive_fd) {
7537 /* Waits for completion, then fg's main shell */
7538 rcode = checkjobs_and_fg_shell(pi);
7539 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7540 check_and_run_traps();
7541 } else
7542#endif
7543 { /* This one just waits for completion */
7544 rcode = checkjobs(pi);
7545 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7546 check_and_run_traps();
7547 }
7548 G.last_exitcode = rcode;
7549 }
7550 }
7551
7552 /* Analyze how result affects subsequent commands */
7553#if ENABLE_HUSH_IF
7554 if (rword == RES_IF || rword == RES_ELIF)
7555 cond_code = rcode;
7556#endif
7557 check_jobs_and_continue:
7558 checkjobs(NULL);
7559 dont_check_jobs_but_continue: ;
7560#if ENABLE_HUSH_LOOPS
7561 /* Beware of "while false; true; do ..."! */
7562 if (pi->next
7563 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
7564 /* check for RES_DONE is needed for "while ...; do \n done" case */
7565 ) {
7566 if (rword == RES_WHILE) {
7567 if (rcode) {
7568 /* "while false; do...done" - exitcode 0 */
7569 G.last_exitcode = rcode = EXIT_SUCCESS;
7570 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7571 break;
7572 }
7573 }
7574 if (rword == RES_UNTIL) {
7575 if (!rcode) {
7576 debug_printf_exec(": until expr is true: breaking\n");
7577 break;
7578 }
7579 }
7580 }
7581#endif
7582 } /* for (pi) */
7583
7584#if ENABLE_HUSH_JOB
7585 G.run_list_level--;
7586#endif
7587#if ENABLE_HUSH_LOOPS
7588 if (loop_top)
7589 G.depth_of_loop--;
7590 free(for_list);
7591#endif
7592#if ENABLE_HUSH_CASE
7593 free(case_word);
7594#endif
7595 debug_leave();
7596 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7597 return rcode;
7598}
7599
7600/* Select which version we will use */
7601static int run_and_free_list(struct pipe *pi)
7602{
7603 int rcode = 0;
7604 debug_printf_exec("run_and_free_list entered\n");
7605 if (!G.o_opt[OPT_O_NOEXEC]) {
7606 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7607 rcode = run_list(pi);
7608 }
7609 /* free_pipe_list has the side effect of clearing memory.
7610 * In the long run that function can be merged with run_list,
7611 * but doing that now would hobble the debugging effort. */
7612 free_pipe_list(pi);
7613 debug_printf_exec("run_and_free_list return %d\n", rcode);
7614 return rcode;
7615}
7616
7617
7618static void install_sighandlers(unsigned mask)
7619{
7620 sighandler_t old_handler;
7621 unsigned sig = 0;
7622 while ((mask >>= 1) != 0) {
7623 sig++;
7624 if (!(mask & 1))
7625 continue;
7626 old_handler = install_sighandler(sig, pick_sighandler(sig));
7627 /* POSIX allows shell to re-enable SIGCHLD
7628 * even if it was SIG_IGN on entry.
7629 * Therefore we skip IGN check for it:
7630 */
7631 if (sig == SIGCHLD)
7632 continue;
7633 if (old_handler == SIG_IGN) {
7634 /* oops... restore back to IGN, and record this fact */
7635 install_sighandler(sig, old_handler);
7636 if (!G.traps)
7637 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7638 free(G.traps[sig]);
7639 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7640 }
7641 }
7642}
7643
7644/* Called a few times only (or even once if "sh -c") */
7645static void install_special_sighandlers(void)
7646{
7647 unsigned mask;
7648
7649 /* Which signals are shell-special? */
7650 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
7651 if (G_interactive_fd) {
7652 mask |= SPECIAL_INTERACTIVE_SIGS;
7653 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7654 mask |= SPECIAL_JOBSTOP_SIGS;
7655 }
7656 /* Careful, do not re-install handlers we already installed */
7657 if (G.special_sig_mask != mask) {
7658 unsigned diff = mask & ~G.special_sig_mask;
7659 G.special_sig_mask = mask;
7660 install_sighandlers(diff);
7661 }
7662}
7663
7664#if ENABLE_HUSH_JOB
7665/* helper */
7666/* Set handlers to restore tty pgrp and exit */
7667static void install_fatal_sighandlers(void)
7668{
7669 unsigned mask;
7670
7671 /* We will restore tty pgrp on these signals */
7672 mask = 0
7673 + (1 << SIGILL ) * HUSH_DEBUG
7674 + (1 << SIGFPE ) * HUSH_DEBUG
7675 + (1 << SIGBUS ) * HUSH_DEBUG
7676 + (1 << SIGSEGV) * HUSH_DEBUG
7677 + (1 << SIGTRAP) * HUSH_DEBUG
7678 + (1 << SIGABRT)
7679 /* bash 3.2 seems to handle these just like 'fatal' ones */
7680 + (1 << SIGPIPE)
7681 + (1 << SIGALRM)
7682 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
7683 * if we aren't interactive... but in this case
7684 * we never want to restore pgrp on exit, and this fn is not called
7685 */
7686 /*+ (1 << SIGHUP )*/
7687 /*+ (1 << SIGTERM)*/
7688 /*+ (1 << SIGINT )*/
7689 ;
7690 G_fatal_sig_mask = mask;
7691
7692 install_sighandlers(mask);
7693}
7694#endif
7695
7696static int set_mode(int state, char mode, const char *o_opt)
7697{
7698 int idx;
7699 switch (mode) {
7700 case 'n':
7701 G.o_opt[OPT_O_NOEXEC] = state;
7702 break;
7703 case 'x':
7704 IF_HUSH_MODE_X(G_x_mode = state;)
7705 break;
7706 case 'o':
7707 if (!o_opt) {
7708 /* "set -+o" without parameter.
7709 * in bash, set -o produces this output:
7710 * pipefail off
7711 * and set +o:
7712 * set +o pipefail
7713 * We always use the second form.
7714 */
7715 const char *p = o_opt_strings;
7716 idx = 0;
7717 while (*p) {
7718 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7719 idx++;
7720 p += strlen(p) + 1;
7721 }
7722 break;
7723 }
7724 idx = index_in_strings(o_opt_strings, o_opt);
7725 if (idx >= 0) {
7726 G.o_opt[idx] = state;
7727 break;
7728 }
7729 default:
7730 return EXIT_FAILURE;
7731 }
7732 return EXIT_SUCCESS;
7733}
7734
7735int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7736int hush_main(int argc, char **argv)
7737{
7738 enum {
7739 OPT_login = (1 << 0),
7740 };
7741 unsigned flags;
7742 int opt;
7743 unsigned builtin_argc;
7744 char **e;
7745 struct variable *cur_var;
7746 struct variable *shell_ver;
7747
7748 INIT_G();
7749 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
7750 G.last_exitcode = EXIT_SUCCESS;
7751#if ENABLE_HUSH_FAST
7752 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7753#endif
7754#if !BB_MMU
7755 G.argv0_for_re_execing = argv[0];
7756#endif
7757 /* Deal with HUSH_VERSION */
7758 shell_ver = xzalloc(sizeof(*shell_ver));
7759 shell_ver->flg_export = 1;
7760 shell_ver->flg_read_only = 1;
7761 /* Code which handles ${var<op>...} needs writable values for all variables,
7762 * therefore we xstrdup: */
7763 shell_ver->varstr = xstrdup(hush_version_str);
7764 /* Create shell local variables from the values
7765 * currently living in the environment */
7766 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7767 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7768 G.top_var = shell_ver;
7769 cur_var = G.top_var;
7770 e = environ;
7771 if (e) while (*e) {
7772 char *value = strchr(*e, '=');
7773 if (value) { /* paranoia */
7774 cur_var->next = xzalloc(sizeof(*cur_var));
7775 cur_var = cur_var->next;
7776 cur_var->varstr = *e;
7777 cur_var->max_len = strlen(*e);
7778 cur_var->flg_export = 1;
7779 }
7780 e++;
7781 }
7782 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7783 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
7784 putenv(shell_ver->varstr);
7785
7786 /* Export PWD */
7787 set_pwd_var(/*exp:*/ 1);
7788 /* bash also exports SHLVL and _,
7789 * and sets (but doesn't export) the following variables:
7790 * BASH=/bin/bash
7791 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7792 * BASH_VERSION='3.2.0(1)-release'
7793 * HOSTTYPE=i386
7794 * MACHTYPE=i386-pc-linux-gnu
7795 * OSTYPE=linux-gnu
7796 * HOSTNAME=<xxxxxxxxxx>
7797 * PPID=<NNNNN> - we also do it elsewhere
7798 * EUID=<NNNNN>
7799 * UID=<NNNNN>
7800 * GROUPS=()
7801 * LINES=<NNN>
7802 * COLUMNS=<NNN>
7803 * BASH_ARGC=()
7804 * BASH_ARGV=()
7805 * BASH_LINENO=()
7806 * BASH_SOURCE=()
7807 * DIRSTACK=()
7808 * PIPESTATUS=([0]="0")
7809 * HISTFILE=/<xxx>/.bash_history
7810 * HISTFILESIZE=500
7811 * HISTSIZE=500
7812 * MAILCHECK=60
7813 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7814 * SHELL=/bin/bash
7815 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7816 * TERM=dumb
7817 * OPTERR=1
7818 * OPTIND=1
7819 * IFS=$' \t\n'
7820 * PS1='\s-\v\$ '
7821 * PS2='> '
7822 * PS4='+ '
7823 */
7824
7825#if ENABLE_FEATURE_EDITING
7826 G.line_input_state = new_line_input_t(FOR_SHELL);
7827#endif
7828
7829 /* Initialize some more globals to non-zero values */
7830 cmdedit_update_prompt();
7831
7832 if (setjmp(die_jmp)) {
7833 /* xfunc has failed! die die die */
7834 /* no EXIT traps, this is an escape hatch! */
7835 G.exiting = 1;
7836 hush_exit(xfunc_error_retval);
7837 }
7838
7839 /* Shell is non-interactive at first. We need to call
7840 * install_special_sighandlers() if we are going to execute "sh <script>",
7841 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7842 * If we later decide that we are interactive, we run install_special_sighandlers()
7843 * in order to intercept (more) signals.
7844 */
7845
7846 /* Parse options */
7847 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7848 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
7849 builtin_argc = 0;
7850 while (1) {
7851 opt = getopt(argc, argv, "+c:xinsl"
7852#if !BB_MMU
7853 "<:$:R:V:"
7854# if ENABLE_HUSH_FUNCTIONS
7855 "F:"
7856# endif
7857#endif
7858 );
7859 if (opt <= 0)
7860 break;
7861 switch (opt) {
7862 case 'c':
7863 /* Possibilities:
7864 * sh ... -c 'script'
7865 * sh ... -c 'script' ARG0 [ARG1...]
7866 * On NOMMU, if builtin_argc != 0,
7867 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7868 * "" needs to be replaced with NULL
7869 * and BARGV vector fed to builtin function.
7870 * Note: the form without ARG0 never happens:
7871 * sh ... -c 'builtin' BARGV... ""
7872 */
7873 if (!G.root_pid) {
7874 G.root_pid = getpid();
7875 G.root_ppid = getppid();
7876 }
7877 G.global_argv = argv + optind;
7878 G.global_argc = argc - optind;
7879 if (builtin_argc) {
7880 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7881 const struct built_in_command *x;
7882
7883 install_special_sighandlers();
7884 x = find_builtin(optarg);
7885 if (x) { /* paranoia */
7886 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7887 G.global_argv += builtin_argc;
7888 G.global_argv[-1] = NULL; /* replace "" */
7889 fflush_all();
7890 G.last_exitcode = x->b_function(argv + optind - 1);
7891 }
7892 goto final_return;
7893 }
7894 if (!G.global_argv[0]) {
7895 /* -c 'script' (no params): prevent empty $0 */
7896 G.global_argv--; /* points to argv[i] of 'script' */
7897 G.global_argv[0] = argv[0];
7898 G.global_argc++;
7899 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7900 install_special_sighandlers();
7901 parse_and_run_string(optarg);
7902 goto final_return;
7903 case 'i':
7904 /* Well, we cannot just declare interactiveness,
7905 * we have to have some stuff (ctty, etc) */
7906 /* G_interactive_fd++; */
7907 break;
7908 case 's':
7909 /* "-s" means "read from stdin", but this is how we always
7910 * operate, so simply do nothing here. */
7911 break;
7912 case 'l':
7913 flags |= OPT_login;
7914 break;
7915#if !BB_MMU
7916 case '<': /* "big heredoc" support */
7917 full_write1_str(optarg);
7918 _exit(0);
7919 case '$': {
7920 unsigned long long empty_trap_mask;
7921
7922 G.root_pid = bb_strtou(optarg, &optarg, 16);
7923 optarg++;
7924 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7925 optarg++;
7926 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7927 optarg++;
7928 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7929 optarg++;
7930 builtin_argc = bb_strtou(optarg, &optarg, 16);
7931 optarg++;
7932 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7933 if (empty_trap_mask != 0) {
7934 int sig;
7935 install_special_sighandlers();
7936 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7937 for (sig = 1; sig < NSIG; sig++) {
7938 if (empty_trap_mask & (1LL << sig)) {
7939 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7940 install_sighandler(sig, SIG_IGN);
7941 }
7942 }
7943 }
7944# if ENABLE_HUSH_LOOPS
7945 optarg++;
7946 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7947# endif
7948 break;
7949 }
7950 case 'R':
7951 case 'V':
7952 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7953 break;
7954# if ENABLE_HUSH_FUNCTIONS
7955 case 'F': {
7956 struct function *funcp = new_function(optarg);
7957 /* funcp->name is already set to optarg */
7958 /* funcp->body is set to NULL. It's a special case. */
7959 funcp->body_as_string = argv[optind];
7960 optind++;
7961 break;
7962 }
7963# endif
7964#endif
7965 case 'n':
7966 case 'x':
7967 if (set_mode(1, opt, NULL) == 0) /* no error */
7968 break;
7969 default:
7970#ifndef BB_VER
7971 fprintf(stderr, "Usage: sh [FILE]...\n"
7972 " or: sh -c command [args]...\n\n");
7973 exit(EXIT_FAILURE);
7974#else
7975 bb_show_usage();
7976#endif
7977 }
7978 } /* option parsing loop */
7979
7980 /* Skip options. Try "hush -l": $1 should not be "-l"! */
7981 G.global_argc = argc - (optind - 1);
7982 G.global_argv = argv + (optind - 1);
7983 G.global_argv[0] = argv[0];
7984
7985 if (!G.root_pid) {
7986 G.root_pid = getpid();
7987 G.root_ppid = getppid();
7988 }
7989
7990 /* If we are login shell... */
7991 if (flags & OPT_login) {
7992 FILE *input;
7993 debug_printf("sourcing /etc/profile\n");
7994 input = fopen_for_read("/etc/profile");
7995 if (input != NULL) {
7996 close_on_exec_on(fileno(input));
7997 install_special_sighandlers();
7998 parse_and_run_file(input);
7999 fclose(input);
8000 }
8001 /* bash: after sourcing /etc/profile,
8002 * tries to source (in the given order):
8003 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8004 * stopping on first found. --noprofile turns this off.
8005 * bash also sources ~/.bash_logout on exit.
8006 * If called as sh, skips .bash_XXX files.
8007 */
8008 }
8009
8010 if (G.global_argv[1]) {
8011 FILE *input;
8012 /*
8013 * "bash <script>" (which is never interactive (unless -i?))
8014 * sources $BASH_ENV here (without scanning $PATH).
8015 * If called as sh, does the same but with $ENV.
8016 */
8017 G.global_argc--;
8018 G.global_argv++;
8019 debug_printf("running script '%s'\n", G.global_argv[0]);
8020 input = xfopen_for_read(G.global_argv[0]);
8021 close_on_exec_on(fileno(input));
8022 install_special_sighandlers();
8023 parse_and_run_file(input);
8024#if ENABLE_FEATURE_CLEAN_UP
8025 fclose(input);
8026#endif
8027 goto final_return;
8028 }
8029
8030 /* Up to here, shell was non-interactive. Now it may become one.
8031 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8032 */
8033
8034 /* A shell is interactive if the '-i' flag was given,
8035 * or if all of the following conditions are met:
8036 * no -c command
8037 * no arguments remaining or the -s flag given
8038 * standard input is a terminal
8039 * standard output is a terminal
8040 * Refer to Posix.2, the description of the 'sh' utility.
8041 */
8042#if ENABLE_HUSH_JOB
8043 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8044 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8045 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8046 if (G_saved_tty_pgrp < 0)
8047 G_saved_tty_pgrp = 0;
8048
8049 /* try to dup stdin to high fd#, >= 255 */
8050 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8051 if (G_interactive_fd < 0) {
8052 /* try to dup to any fd */
8053 G_interactive_fd = dup(STDIN_FILENO);
8054 if (G_interactive_fd < 0) {
8055 /* give up */
8056 G_interactive_fd = 0;
8057 G_saved_tty_pgrp = 0;
8058 }
8059 }
8060// TODO: track & disallow any attempts of user
8061// to (inadvertently) close/redirect G_interactive_fd
8062 }
8063 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8064 if (G_interactive_fd) {
8065 close_on_exec_on(G_interactive_fd);
8066
8067 if (G_saved_tty_pgrp) {
8068 /* If we were run as 'hush &', sleep until we are
8069 * in the foreground (tty pgrp == our pgrp).
8070 * If we get started under a job aware app (like bash),
8071 * make sure we are now in charge so we don't fight over
8072 * who gets the foreground */
8073 while (1) {
8074 pid_t shell_pgrp = getpgrp();
8075 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8076 if (G_saved_tty_pgrp == shell_pgrp)
8077 break;
8078 /* send TTIN to ourself (should stop us) */
8079 kill(- shell_pgrp, SIGTTIN);
8080 }
8081 }
8082
8083 /* Install more signal handlers */
8084 install_special_sighandlers();
8085
8086 if (G_saved_tty_pgrp) {
8087 /* Set other signals to restore saved_tty_pgrp */
8088 install_fatal_sighandlers();
8089 /* Put ourselves in our own process group
8090 * (bash, too, does this only if ctty is available) */
8091 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8092 /* Grab control of the terminal */
8093 tcsetpgrp(G_interactive_fd, getpid());
8094 }
8095 /* -1 is special - makes xfuncs longjmp, not exit
8096 * (we reset die_sleep = 0 whereever we [v]fork) */
8097 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
8098
8099# if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8100 {
8101 const char *hp = get_local_var_value("HISTFILE");
8102 if (!hp) {
8103 hp = get_local_var_value("HOME");
8104 if (hp)
8105 hp = concat_path_file(hp, ".hush_history");
8106 } else {
8107 hp = xstrdup(hp);
8108 }
8109 if (hp) {
8110 G.line_input_state->hist_file = hp;
8111 //set_local_var(xasprintf("HISTFILE=%s", ...));
8112 }
8113# if ENABLE_FEATURE_SH_HISTFILESIZE
8114 hp = get_local_var_value("HISTFILESIZE");
8115 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8116# endif
8117 }
8118# endif
8119 } else {
8120 install_special_sighandlers();
8121 }
8122#elif ENABLE_HUSH_INTERACTIVE
8123 /* No job control compiled in, only prompt/line editing */
8124 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8125 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8126 if (G_interactive_fd < 0) {
8127 /* try to dup to any fd */
8128 G_interactive_fd = dup(STDIN_FILENO);
8129 if (G_interactive_fd < 0)
8130 /* give up */
8131 G_interactive_fd = 0;
8132 }
8133 }
8134 if (G_interactive_fd) {
8135 close_on_exec_on(G_interactive_fd);
8136 }
8137 install_special_sighandlers();
8138#else
8139 /* We have interactiveness code disabled */
8140 install_special_sighandlers();
8141#endif
8142 /* bash:
8143 * if interactive but not a login shell, sources ~/.bashrc
8144 * (--norc turns this off, --rcfile <file> overrides)
8145 */
8146
8147 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8148 /* note: ash and hush share this string */
8149 printf("\n\n%s %s\n"
8150 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8151 "\n",
8152 bb_banner,
8153 "hush - the humble shell"
8154 );
8155 }
8156
8157 parse_and_run_file(stdin);
8158
8159 final_return:
8160 hush_exit(G.last_exitcode);
8161}
8162
8163
8164#if ENABLE_MSH
8165int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8166int msh_main(int argc, char **argv)
8167{
8168 //bb_error_msg("msh is deprecated, please use hush instead");
8169 return hush_main(argc, argv);
8170}
8171#endif
8172
8173
8174/*
8175 * Built-ins
8176 */
8177static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8178{
8179 return 0;
8180}
8181
8182static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8183{
8184 int argc = 0;
8185 while (*argv) {
8186 argc++;
8187 argv++;
8188 }
8189 return applet_main_func(argc, argv - argc);
8190}
8191
8192static int FAST_FUNC builtin_test(char **argv)
8193{
8194 return run_applet_main(argv, test_main);
8195}
8196
8197static int FAST_FUNC builtin_echo(char **argv)
8198{
8199 return run_applet_main(argv, echo_main);
8200}
8201
8202#if ENABLE_PRINTF
8203static int FAST_FUNC builtin_printf(char **argv)
8204{
8205 return run_applet_main(argv, printf_main);
8206}
8207#endif
8208
8209static char **skip_dash_dash(char **argv)
8210{
8211 argv++;
8212 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8213 argv++;
8214 return argv;
8215}
8216
8217static int FAST_FUNC builtin_eval(char **argv)
8218{
8219 int rcode = EXIT_SUCCESS;
8220
8221 argv = skip_dash_dash(argv);
8222 if (*argv) {
8223 char *str = expand_strvec_to_string(argv);
8224 /* bash:
8225 * eval "echo Hi; done" ("done" is syntax error):
8226 * "echo Hi" will not execute too.
8227 */
8228 parse_and_run_string(str);
8229 free(str);
8230 rcode = G.last_exitcode;
8231 }
8232 return rcode;
8233}
8234
8235static int FAST_FUNC builtin_cd(char **argv)
8236{
8237 const char *newdir;
8238
8239 argv = skip_dash_dash(argv);
8240 newdir = argv[0];
8241 if (newdir == NULL) {
8242 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8243 * bash says "bash: cd: HOME not set" and does nothing
8244 * (exitcode 1)
8245 */
8246 const char *home = get_local_var_value("HOME");
8247 newdir = home ? home : "/";
8248 }
8249 if (chdir(newdir)) {
8250 /* Mimic bash message exactly */
8251 bb_perror_msg("cd: %s", newdir);
8252 return EXIT_FAILURE;
8253 }
8254 /* Read current dir (get_cwd(1) is inside) and set PWD.
8255 * Note: do not enforce exporting. If PWD was unset or unexported,
8256 * set it again, but do not export. bash does the same.
8257 */
8258 set_pwd_var(/*exp:*/ 0);
8259 return EXIT_SUCCESS;
8260}
8261
8262static int FAST_FUNC builtin_exec(char **argv)
8263{
8264 argv = skip_dash_dash(argv);
8265 if (argv[0] == NULL)
8266 return EXIT_SUCCESS; /* bash does this */
8267
8268 /* Careful: we can end up here after [v]fork. Do not restore
8269 * tty pgrp then, only top-level shell process does that */
8270 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8271 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8272
8273 /* TODO: if exec fails, bash does NOT exit! We do.
8274 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8275 * and tcsetpgrp, and this is inherently racy.
8276 */
8277 execvp_or_die(argv);
8278}
8279
8280static int FAST_FUNC builtin_exit(char **argv)
8281{
8282 debug_printf_exec("%s()\n", __func__);
8283
8284 /* interactive bash:
8285 * # trap "echo EEE" EXIT
8286 * # exit
8287 * exit
8288 * There are stopped jobs.
8289 * (if there are _stopped_ jobs, running ones don't count)
8290 * # exit
8291 * exit
8292 * EEE (then bash exits)
8293 *
8294 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8295 */
8296
8297 /* note: EXIT trap is run by hush_exit */
8298 argv = skip_dash_dash(argv);
8299 if (argv[0] == NULL)
8300 hush_exit(G.last_exitcode);
8301 /* mimic bash: exit 123abc == exit 255 + error msg */
8302 xfunc_error_retval = 255;
8303 /* bash: exit -2 == exit 254, no error msg */
8304 hush_exit(xatoi(argv[0]) & 0xff);
8305}
8306
8307static void print_escaped(const char *s)
8308{
8309 if (*s == '\'')
8310 goto squote;
8311 do {
8312 const char *p = strchrnul(s, '\'');
8313 /* print 'xxxx', possibly just '' */
8314 printf("'%.*s'", (int)(p - s), s);
8315 if (*p == '\0')
8316 break;
8317 s = p;
8318 squote:
8319 /* s points to '; print "'''...'''" */
8320 putchar('"');
8321 do putchar('\''); while (*++s == '\'');
8322 putchar('"');
8323 } while (*s);
8324}
8325
8326#if !ENABLE_HUSH_LOCAL
8327#define helper_export_local(argv, exp, lvl) \
8328 helper_export_local(argv, exp)
8329#endif
8330static void helper_export_local(char **argv, int exp, int lvl)
8331{
8332 do {
8333 char *name = *argv;
8334 char *name_end = strchrnul(name, '=');
8335
8336 /* So far we do not check that name is valid (TODO?) */
8337
8338 if (*name_end == '\0') {
8339 struct variable *var, **vpp;
8340
8341 vpp = get_ptr_to_local_var(name, name_end - name);
8342 var = vpp ? *vpp : NULL;
8343
8344 if (exp == -1) { /* unexporting? */
8345 /* export -n NAME (without =VALUE) */
8346 if (var) {
8347 var->flg_export = 0;
8348 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8349 unsetenv(name);
8350 } /* else: export -n NOT_EXISTING_VAR: no-op */
8351 continue;
8352 }
8353 if (exp == 1) { /* exporting? */
8354 /* export NAME (without =VALUE) */
8355 if (var) {
8356 var->flg_export = 1;
8357 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8358 putenv(var->varstr);
8359 continue;
8360 }
8361 }
8362 /* Exporting non-existing variable.
8363 * bash does not put it in environment,
8364 * but remembers that it is exported,
8365 * and does put it in env when it is set later.
8366 * We just set it to "" and export. */
8367 /* Or, it's "local NAME" (without =VALUE).
8368 * bash sets the value to "". */
8369 name = xasprintf("%s=", name);
8370 } else {
8371 /* (Un)exporting/making local NAME=VALUE */
8372 name = xstrdup(name);
8373 }
8374 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8375 } while (*++argv);
8376}
8377
8378static int FAST_FUNC builtin_export(char **argv)
8379{
8380 unsigned opt_unexport;
8381
8382#if ENABLE_HUSH_EXPORT_N
8383 /* "!": do not abort on errors */
8384 opt_unexport = getopt32(argv, "!n");
8385 if (opt_unexport == (uint32_t)-1)
8386 return EXIT_FAILURE;
8387 argv += optind;
8388#else
8389 opt_unexport = 0;
8390 argv++;
8391#endif
8392
8393 if (argv[0] == NULL) {
8394 char **e = environ;
8395 if (e) {
8396 while (*e) {
8397#if 0
8398 puts(*e++);
8399#else
8400 /* ash emits: export VAR='VAL'
8401 * bash: declare -x VAR="VAL"
8402 * we follow ash example */
8403 const char *s = *e++;
8404 const char *p = strchr(s, '=');
8405
8406 if (!p) /* wtf? take next variable */
8407 continue;
8408 /* export var= */
8409 printf("export %.*s", (int)(p - s) + 1, s);
8410 print_escaped(p + 1);
8411 putchar('\n');
8412#endif
8413 }
8414 /*fflush_all(); - done after each builtin anyway */
8415 }
8416 return EXIT_SUCCESS;
8417 }
8418
8419 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8420
8421 return EXIT_SUCCESS;
8422}
8423
8424#if ENABLE_HUSH_LOCAL
8425static int FAST_FUNC builtin_local(char **argv)
8426{
8427 if (G.func_nest_level == 0) {
8428 bb_error_msg("%s: not in a function", argv[0]);
8429 return EXIT_FAILURE; /* bash compat */
8430 }
8431 helper_export_local(argv, 0, G.func_nest_level);
8432 return EXIT_SUCCESS;
8433}
8434#endif
8435
8436static int FAST_FUNC builtin_trap(char **argv)
8437{
8438 int sig;
8439 char *new_cmd;
8440
8441 if (!G.traps)
8442 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8443
8444 argv++;
8445 if (!*argv) {
8446 int i;
8447 /* No args: print all trapped */
8448 for (i = 0; i < NSIG; ++i) {
8449 if (G.traps[i]) {
8450 printf("trap -- ");
8451 print_escaped(G.traps[i]);
8452 /* note: bash adds "SIG", but only if invoked
8453 * as "bash". If called as "sh", or if set -o posix,
8454 * then it prints short signal names.
8455 * We are printing short names: */
8456 printf(" %s\n", get_signame(i));
8457 }
8458 }
8459 /*fflush_all(); - done after each builtin anyway */
8460 return EXIT_SUCCESS;
8461 }
8462
8463 new_cmd = NULL;
8464 /* If first arg is a number: reset all specified signals */
8465 sig = bb_strtou(*argv, NULL, 10);
8466 if (errno == 0) {
8467 int ret;
8468 process_sig_list:
8469 ret = EXIT_SUCCESS;
8470 while (*argv) {
8471 sighandler_t handler;
8472
8473 sig = get_signum(*argv++);
8474 if (sig < 0 || sig >= NSIG) {
8475 ret = EXIT_FAILURE;
8476 /* Mimic bash message exactly */
8477 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8478 continue;
8479 }
8480
8481 free(G.traps[sig]);
8482 G.traps[sig] = xstrdup(new_cmd);
8483
8484 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8485 get_signame(sig), sig, G.traps[sig]);
8486
8487 /* There is no signal for 0 (EXIT) */
8488 if (sig == 0)
8489 continue;
8490
8491 if (new_cmd)
8492 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
8493 else
8494 /* We are removing trap handler */
8495 handler = pick_sighandler(sig);
8496 install_sighandler(sig, handler);
8497 }
8498 return ret;
8499 }
8500
8501 if (!argv[1]) { /* no second arg */
8502 bb_error_msg("trap: invalid arguments");
8503 return EXIT_FAILURE;
8504 }
8505
8506 /* First arg is "-": reset all specified to default */
8507 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8508 /* Everything else: set arg as signal handler
8509 * (includes "" case, which ignores signal) */
8510 if (argv[0][0] == '-') {
8511 if (argv[0][1] == '\0') { /* "-" */
8512 /* new_cmd remains NULL: "reset these sigs" */
8513 goto reset_traps;
8514 }
8515 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8516 argv++;
8517 }
8518 /* else: "-something", no special meaning */
8519 }
8520 new_cmd = *argv;
8521 reset_traps:
8522 argv++;
8523 goto process_sig_list;
8524}
8525
8526/* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8527static int FAST_FUNC builtin_type(char **argv)
8528{
8529 int ret = EXIT_SUCCESS;
8530
8531 while (*++argv) {
8532 const char *type;
8533 char *path = NULL;
8534
8535 if (0) {} /* make conditional compile easier below */
8536 /*else if (find_alias(*argv))
8537 type = "an alias";*/
8538#if ENABLE_HUSH_FUNCTIONS
8539 else if (find_function(*argv))
8540 type = "a function";
8541#endif
8542 else if (find_builtin(*argv))
8543 type = "a shell builtin";
8544 else if ((path = find_in_path(*argv)) != NULL)
8545 type = path;
8546 else {
8547 bb_error_msg("type: %s: not found", *argv);
8548 ret = EXIT_FAILURE;
8549 continue;
8550 }
8551
8552 printf("%s is %s\n", *argv, type);
8553 free(path);
8554 }
8555
8556 return ret;
8557}
8558
8559#if ENABLE_HUSH_JOB
8560/* built-in 'fg' and 'bg' handler */
8561static int FAST_FUNC builtin_fg_bg(char **argv)
8562{
8563 int i, jobnum;
8564 struct pipe *pi;
8565
8566 if (!G_interactive_fd)
8567 return EXIT_FAILURE;
8568
8569 /* If they gave us no args, assume they want the last backgrounded task */
8570 if (!argv[1]) {
8571 for (pi = G.job_list; pi; pi = pi->next) {
8572 if (pi->jobid == G.last_jobid) {
8573 goto found;
8574 }
8575 }
8576 bb_error_msg("%s: no current job", argv[0]);
8577 return EXIT_FAILURE;
8578 }
8579 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8580 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8581 return EXIT_FAILURE;
8582 }
8583 for (pi = G.job_list; pi; pi = pi->next) {
8584 if (pi->jobid == jobnum) {
8585 goto found;
8586 }
8587 }
8588 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8589 return EXIT_FAILURE;
8590 found:
8591 /* TODO: bash prints a string representation
8592 * of job being foregrounded (like "sleep 1 | cat") */
8593 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8594 /* Put the job into the foreground. */
8595 tcsetpgrp(G_interactive_fd, pi->pgrp);
8596 }
8597
8598 /* Restart the processes in the job */
8599 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8600 for (i = 0; i < pi->num_cmds; i++) {
8601 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8602 }
8603 pi->stopped_cmds = 0;
8604
8605 i = kill(- pi->pgrp, SIGCONT);
8606 if (i < 0) {
8607 if (errno == ESRCH) {
8608 delete_finished_bg_job(pi);
8609 return EXIT_SUCCESS;
8610 }
8611 bb_perror_msg("kill (SIGCONT)");
8612 }
8613
8614 if (argv[0][0] == 'f') {
8615 remove_bg_job(pi);
8616 return checkjobs_and_fg_shell(pi);
8617 }
8618 return EXIT_SUCCESS;
8619}
8620#endif
8621
8622#if ENABLE_HUSH_HELP
8623static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8624{
8625 const struct built_in_command *x;
8626
8627 printf(
8628 "Built-in commands:\n"
8629 "------------------\n");
8630 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8631 if (x->b_descr)
8632 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8633 }
8634 bb_putchar('\n');
8635 return EXIT_SUCCESS;
8636}
8637#endif
8638
8639#if MAX_HISTORY && ENABLE_FEATURE_EDITING
8640static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8641{
8642 show_history(G.line_input_state);
8643 return EXIT_SUCCESS;
8644}
8645#endif
8646
8647#if ENABLE_HUSH_JOB
8648static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8649{
8650 struct pipe *job;
8651 const char *status_string;
8652
8653 for (job = G.job_list; job; job = job->next) {
8654 if (job->alive_cmds == job->stopped_cmds)
8655 status_string = "Stopped";
8656 else
8657 status_string = "Running";
8658
8659 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8660 }
8661 return EXIT_SUCCESS;
8662}
8663#endif
8664
8665#if HUSH_DEBUG
8666static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8667{
8668 void *p;
8669 unsigned long l;
8670
8671# ifdef M_TRIM_THRESHOLD
8672 /* Optional. Reduces probability of false positives */
8673 malloc_trim(0);
8674# endif
8675 /* Crude attempt to find where "free memory" starts,
8676 * sans fragmentation. */
8677 p = malloc(240);
8678 l = (unsigned long)p;
8679 free(p);
8680 p = malloc(3400);
8681 if (l < (unsigned long)p) l = (unsigned long)p;
8682 free(p);
8683
8684 if (!G.memleak_value)
8685 G.memleak_value = l;
8686
8687 l -= G.memleak_value;
8688 if ((long)l < 0)
8689 l = 0;
8690 l /= 1024;
8691 if (l > 127)
8692 l = 127;
8693
8694 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8695 return l;
8696}
8697#endif
8698
8699static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8700{
8701 puts(get_cwd(0));
8702 return EXIT_SUCCESS;
8703}
8704
8705/* Interruptibility of read builtin in bash
8706 * (tested on bash-4.2.8 by sending signals (not by ^C)):
8707 *
8708 * Empty trap makes read ignore corresponding signal, for any signal.
8709 *
8710 * SIGINT:
8711 * - terminates non-interactive shell;
8712 * - interrupts read in interactive shell;
8713 * if it has non-empty trap:
8714 * - executes trap and returns to command prompt in interactive shell;
8715 * - executes trap and returns to read in non-interactive shell;
8716 * SIGTERM:
8717 * - is ignored (does not interrupt) read in interactive shell;
8718 * - terminates non-interactive shell;
8719 * if it has non-empty trap:
8720 * - executes trap and returns to read;
8721 * SIGHUP:
8722 * - terminates shell (regardless of interactivity);
8723 * if it has non-empty trap:
8724 * - executes trap and returns to read;
8725 */
8726static int FAST_FUNC builtin_read(char **argv)
8727{
8728 const char *r;
8729 char *opt_n = NULL;
8730 char *opt_p = NULL;
8731 char *opt_t = NULL;
8732 char *opt_u = NULL;
8733 const char *ifs;
8734 int read_flags;
8735
8736 /* "!": do not abort on errors.
8737 * Option string must start with "sr" to match BUILTIN_READ_xxx
8738 */
8739 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8740 if (read_flags == (uint32_t)-1)
8741 return EXIT_FAILURE;
8742 argv += optind;
8743 ifs = get_local_var_value("IFS"); /* can be NULL */
8744
8745 again:
8746 r = shell_builtin_read(set_local_var_from_halves,
8747 argv,
8748 ifs,
8749 read_flags,
8750 opt_n,
8751 opt_p,
8752 opt_t,
8753 opt_u
8754 );
8755
8756 if ((uintptr_t)r == 1 && errno == EINTR) {
8757 unsigned sig = check_and_run_traps();
8758 if (sig && sig != SIGINT)
8759 goto again;
8760 }
8761
8762 if ((uintptr_t)r > 1) {
8763 bb_error_msg("%s", r);
8764 r = (char*)(uintptr_t)1;
8765 }
8766
8767 return (uintptr_t)r;
8768}
8769
8770/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8771 * built-in 'set' handler
8772 * SUSv3 says:
8773 * set [-abCefhmnuvx] [-o option] [argument...]
8774 * set [+abCefhmnuvx] [+o option] [argument...]
8775 * set -- [argument...]
8776 * set -o
8777 * set +o
8778 * Implementations shall support the options in both their hyphen and
8779 * plus-sign forms. These options can also be specified as options to sh.
8780 * Examples:
8781 * Write out all variables and their values: set
8782 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8783 * Turn on the -x and -v options: set -xv
8784 * Unset all positional parameters: set --
8785 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8786 * Set the positional parameters to the expansion of x, even if x expands
8787 * with a leading '-' or '+': set -- $x
8788 *
8789 * So far, we only support "set -- [argument...]" and some of the short names.
8790 */
8791static int FAST_FUNC builtin_set(char **argv)
8792{
8793 int n;
8794 char **pp, **g_argv;
8795 char *arg = *++argv;
8796
8797 if (arg == NULL) {
8798 struct variable *e;
8799 for (e = G.top_var; e; e = e->next)
8800 puts(e->varstr);
8801 return EXIT_SUCCESS;
8802 }
8803
8804 do {
8805 if (strcmp(arg, "--") == 0) {
8806 ++argv;
8807 goto set_argv;
8808 }
8809 if (arg[0] != '+' && arg[0] != '-')
8810 break;
8811 for (n = 1; arg[n]; ++n) {
8812 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8813 goto error;
8814 if (arg[n] == 'o' && argv[1])
8815 argv++;
8816 }
8817 } while ((arg = *++argv) != NULL);
8818 /* Now argv[0] is 1st argument */
8819
8820 if (arg == NULL)
8821 return EXIT_SUCCESS;
8822 set_argv:
8823
8824 /* NB: G.global_argv[0] ($0) is never freed/changed */
8825 g_argv = G.global_argv;
8826 if (G.global_args_malloced) {
8827 pp = g_argv;
8828 while (*++pp)
8829 free(*pp);
8830 g_argv[1] = NULL;
8831 } else {
8832 G.global_args_malloced = 1;
8833 pp = xzalloc(sizeof(pp[0]) * 2);
8834 pp[0] = g_argv[0]; /* retain $0 */
8835 g_argv = pp;
8836 }
8837 /* This realloc's G.global_argv */
8838 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8839
8840 n = 1;
8841 while (*++pp)
8842 n++;
8843 G.global_argc = n;
8844
8845 return EXIT_SUCCESS;
8846
8847 /* Nothing known, so abort */
8848 error:
8849 bb_error_msg("set: %s: invalid option", arg);
8850 return EXIT_FAILURE;
8851}
8852
8853static int FAST_FUNC builtin_shift(char **argv)
8854{
8855 int n = 1;
8856 argv = skip_dash_dash(argv);
8857 if (argv[0]) {
8858 n = atoi(argv[0]);
8859 }
8860 if (n >= 0 && n < G.global_argc) {
8861 if (G.global_args_malloced) {
8862 int m = 1;
8863 while (m <= n)
8864 free(G.global_argv[m++]);
8865 }
8866 G.global_argc -= n;
8867 memmove(&G.global_argv[1], &G.global_argv[n+1],
8868 G.global_argc * sizeof(G.global_argv[0]));
8869 return EXIT_SUCCESS;
8870 }
8871 return EXIT_FAILURE;
8872}
8873
8874static int FAST_FUNC builtin_source(char **argv)
8875{
8876 char *arg_path, *filename;
8877 FILE *input;
8878 save_arg_t sv;
8879#if ENABLE_HUSH_FUNCTIONS
8880 smallint sv_flg;
8881#endif
8882
8883 argv = skip_dash_dash(argv);
8884 filename = argv[0];
8885 if (!filename) {
8886 /* bash says: "bash: .: filename argument required" */
8887 return 2; /* bash compat */
8888 }
8889 arg_path = NULL;
8890 if (!strchr(filename, '/')) {
8891 arg_path = find_in_path(filename);
8892 if (arg_path)
8893 filename = arg_path;
8894 }
8895 input = fopen_or_warn(filename, "r");
8896 free(arg_path);
8897 if (!input) {
8898 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8899 /* POSIX: non-interactive shell should abort here,
8900 * not merely fail. So far no one complained :)
8901 */
8902 return EXIT_FAILURE;
8903 }
8904 close_on_exec_on(fileno(input));
8905
8906#if ENABLE_HUSH_FUNCTIONS
8907 sv_flg = G.flag_return_in_progress;
8908 /* "we are inside sourced file, ok to use return" */
8909 G.flag_return_in_progress = -1;
8910#endif
8911 if (argv[1])
8912 save_and_replace_G_args(&sv, argv);
8913
8914 parse_and_run_file(input);
8915 fclose(input);
8916
8917 if (argv[1])
8918 restore_G_args(&sv, argv);
8919#if ENABLE_HUSH_FUNCTIONS
8920 G.flag_return_in_progress = sv_flg;
8921#endif
8922
8923 return G.last_exitcode;
8924}
8925
8926static int FAST_FUNC builtin_umask(char **argv)
8927{
8928 int rc;
8929 mode_t mask;
8930
8931 mask = umask(0);
8932 argv = skip_dash_dash(argv);
8933 if (argv[0]) {
8934 mode_t old_mask = mask;
8935
8936 mask ^= 0777;
8937 rc = bb_parse_mode(argv[0], &mask);
8938 mask ^= 0777;
8939 if (rc == 0) {
8940 mask = old_mask;
8941 /* bash messages:
8942 * bash: umask: 'q': invalid symbolic mode operator
8943 * bash: umask: 999: octal number out of range
8944 */
8945 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8946 }
8947 } else {
8948 rc = 1;
8949 /* Mimic bash */
8950 printf("%04o\n", (unsigned) mask);
8951 /* fall through and restore mask which we set to 0 */
8952 }
8953 umask(mask);
8954
8955 return !rc; /* rc != 0 - success */
8956}
8957
8958/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8959static int FAST_FUNC builtin_unset(char **argv)
8960{
8961 int ret;
8962 unsigned opts;
8963
8964 /* "!": do not abort on errors */
8965 /* "+": stop at 1st non-option */
8966 opts = getopt32(argv, "!+vf");
8967 if (opts == (unsigned)-1)
8968 return EXIT_FAILURE;
8969 if (opts == 3) {
8970 bb_error_msg("unset: -v and -f are exclusive");
8971 return EXIT_FAILURE;
8972 }
8973 argv += optind;
8974
8975 ret = EXIT_SUCCESS;
8976 while (*argv) {
8977 if (!(opts & 2)) { /* not -f */
8978 if (unset_local_var(*argv)) {
8979 /* unset <nonexistent_var> doesn't fail.
8980 * Error is when one tries to unset RO var.
8981 * Message was printed by unset_local_var. */
8982 ret = EXIT_FAILURE;
8983 }
8984 }
8985#if ENABLE_HUSH_FUNCTIONS
8986 else {
8987 unset_func(*argv);
8988 }
8989#endif
8990 argv++;
8991 }
8992 return ret;
8993}
8994
8995/* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8996static int FAST_FUNC builtin_wait(char **argv)
8997{
8998 int ret = EXIT_SUCCESS;
8999 int status;
9000
9001 argv = skip_dash_dash(argv);
9002 if (argv[0] == NULL) {
9003 /* Don't care about wait results */
9004 /* Note 1: must wait until there are no more children */
9005 /* Note 2: must be interruptible */
9006 /* Examples:
9007 * $ sleep 3 & sleep 6 & wait
9008 * [1] 30934 sleep 3
9009 * [2] 30935 sleep 6
9010 * [1] Done sleep 3
9011 * [2] Done sleep 6
9012 * $ sleep 3 & sleep 6 & wait
9013 * [1] 30936 sleep 3
9014 * [2] 30937 sleep 6
9015 * [1] Done sleep 3
9016 * ^C <-- after ~4 sec from keyboard
9017 * $
9018 */
9019 while (1) {
9020 int sig;
9021 sigset_t oldset, allsigs;
9022
9023 /* waitpid is not interruptible by SA_RESTARTed
9024 * signals which we use. Thus, this ugly dance:
9025 */
9026
9027 /* Make sure possible SIGCHLD is stored in kernel's
9028 * pending signal mask before we call waitpid.
9029 * Or else we may race with SIGCHLD, lose it,
9030 * and get stuck in sigwaitinfo...
9031 */
9032 sigfillset(&allsigs);
9033 sigprocmask(SIG_SETMASK, &allsigs, &oldset);
9034
9035 if (!sigisemptyset(&G.pending_set)) {
9036 /* Crap! we raced with some signal! */
9037 // sig = 0;
9038 goto restore;
9039 }
9040
9041 checkjobs(NULL); /* waitpid(WNOHANG) inside */
9042 if (errno == ECHILD) {
9043 sigprocmask(SIG_SETMASK, &oldset, NULL);
9044 break;
9045 }
9046
9047 /* Wait for SIGCHLD or any other signal */
9048 //sig = sigwaitinfo(&allsigs, NULL);
9049 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9050 /* Note: sigsuspend invokes signal handler */
9051 sigsuspend(&oldset);
9052 restore:
9053 sigprocmask(SIG_SETMASK, &oldset, NULL);
9054
9055 /* So, did we get a signal? */
9056 //if (sig > 0)
9057 // raise(sig); /* run handler */
9058 sig = check_and_run_traps();
9059 if (sig /*&& sig != SIGCHLD - always true */) {
9060 /* see note 2 */
9061 ret = 128 + sig;
9062 break;
9063 }
9064 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9065 }
9066 return ret;
9067 }
9068
9069 /* This is probably buggy wrt interruptible-ness */
9070 while (*argv) {
9071 pid_t pid = bb_strtou(*argv, NULL, 10);
9072 if (errno) {
9073 /* mimic bash message */
9074 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9075 return EXIT_FAILURE;
9076 }
9077 if (waitpid(pid, &status, 0) == pid) {
9078 if (WIFSIGNALED(status))
9079 ret = 128 + WTERMSIG(status);
9080 else if (WIFEXITED(status))
9081 ret = WEXITSTATUS(status);
9082 else /* wtf? */
9083 ret = EXIT_FAILURE;
9084 } else {
9085 bb_perror_msg("wait %s", *argv);
9086 ret = 127;
9087 }
9088 argv++;
9089 }
9090
9091 return ret;
9092}
9093
9094#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9095static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9096{
9097 if (argv[1]) {
9098 def = bb_strtou(argv[1], NULL, 10);
9099 if (errno || def < def_min || argv[2]) {
9100 bb_error_msg("%s: bad arguments", argv[0]);
9101 def = UINT_MAX;
9102 }
9103 }
9104 return def;
9105}
9106#endif
9107
9108#if ENABLE_HUSH_LOOPS
9109static int FAST_FUNC builtin_break(char **argv)
9110{
9111 unsigned depth;
9112 if (G.depth_of_loop == 0) {
9113 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9114 return EXIT_SUCCESS; /* bash compat */
9115 }
9116 G.flag_break_continue++; /* BC_BREAK = 1 */
9117
9118 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9119 if (depth == UINT_MAX)
9120 G.flag_break_continue = BC_BREAK;
9121 if (G.depth_of_loop < depth)
9122 G.depth_break_continue = G.depth_of_loop;
9123
9124 return EXIT_SUCCESS;
9125}
9126
9127static int FAST_FUNC builtin_continue(char **argv)
9128{
9129 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9130 return builtin_break(argv);
9131}
9132#endif
9133
9134#if ENABLE_HUSH_FUNCTIONS
9135static int FAST_FUNC builtin_return(char **argv)
9136{
9137 int rc;
9138
9139 if (G.flag_return_in_progress != -1) {
9140 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9141 return EXIT_FAILURE; /* bash compat */
9142 }
9143
9144 G.flag_return_in_progress = 1;
9145
9146 /* bash:
9147 * out of range: wraps around at 256, does not error out
9148 * non-numeric param:
9149 * f() { false; return qwe; }; f; echo $?
9150 * bash: return: qwe: numeric argument required <== we do this
9151 * 255 <== we also do this
9152 */
9153 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
9154 return rc;
9155}
9156#endif
9157
generated by cgit at 2024-05-15 05:22:59 (GMT)