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1/* vi: set sw=4 ts=4: */
2/*
3 * script implementation for busybox
4 *
5 * pascal.bellard@ads-lu.com
6 *
7 * Based on code from util-linux v 2.12r
8 * Copyright (c) 1980
9 * The Regents of the University of California. All rights reserved.
10 *
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
12 */
13//config:config SCRIPT
14//config: bool "script"
15//config: default y
16//config: help
17//config: The script makes typescript of terminal session.
18
19//applet:IF_SCRIPT(APPLET(script, BB_DIR_USR_BIN, BB_SUID_DROP))
20
21//kbuild:lib-$(CONFIG_SCRIPT) += script.o
22
23//usage:#define script_trivial_usage
24//usage: "[-afq" IF_SCRIPTREPLAY("t") "] [-c PROG] [OUTFILE]"
25//usage:#define script_full_usage "\n\n"
26//usage: " -a Append output"
27//usage: "\n -c PROG Run PROG, not shell"
28//usage: "\n -f Flush output after each write"
29//usage: "\n -q Quiet"
30//usage: IF_SCRIPTREPLAY(
31//usage: "\n -t Send timing to stderr"
32//usage: )
33
34#include "libbb.h"
35#include "common_bufsiz.h"
36
37int script_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
38int script_main(int argc UNUSED_PARAM, char **argv)
39{
40 int opt;
41 int mode;
42 int child_pid;
43 int attr_ok; /* NB: 0: ok */
44 int winsz_ok;
45 int pty;
46 char pty_line[GETPTY_BUFSIZE];
47 struct termios tt, rtt;
48 struct winsize win;
49 const char *fname = "typescript";
50 const char *shell;
51 char shell_opt[] = "-i";
52 char *shell_arg = NULL;
53 enum {
54 OPT_a = (1 << 0),
55 OPT_c = (1 << 1),
56 OPT_f = (1 << 2),
57 OPT_q = (1 << 3),
58 OPT_t = (1 << 4),
59 };
60
61#if ENABLE_LONG_OPTS
62 static const char getopt_longopts[] ALIGN1 =
63 "append\0" No_argument "a"
64 "command\0" Required_argument "c"
65 "flush\0" No_argument "f"
66 "quiet\0" No_argument "q"
67 IF_SCRIPTREPLAY("timing\0" No_argument "t")
68 ;
69
70 applet_long_options = getopt_longopts;
71#endif
72
73 opt_complementary = "?1"; /* max one arg */
74 opt = getopt32(argv, "ac:fq" IF_SCRIPTREPLAY("t") , &shell_arg);
75 //argc -= optind;
76 argv += optind;
77 if (argv[0]) {
78 fname = argv[0];
79 }
80 mode = O_CREAT|O_TRUNC|O_WRONLY;
81 if (opt & OPT_a) {
82 mode = O_CREAT|O_APPEND|O_WRONLY;
83 }
84 if (opt & OPT_c) {
85 shell_opt[1] = 'c';
86 }
87 if (!(opt & OPT_q)) {
88 printf("Script started, file is %s\n", fname);
89 }
90
91 shell = get_shell_name();
92
93 /* Some people run "script ... 0>&-".
94 * Our code assumes that STDIN_FILENO != pty.
95 * Ensure STDIN_FILENO is not closed:
96 */
97 bb_sanitize_stdio();
98
99 pty = xgetpty(pty_line);
100
101 /* get current stdin's tty params */
102 attr_ok = tcgetattr(0, &tt);
103 winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);
104
105 rtt = tt;
106 cfmakeraw(&rtt);
107 rtt.c_lflag &= ~ECHO;
108 tcsetattr(0, TCSAFLUSH, &rtt);
109
110 /* "script" from util-linux exits when child exits,
111 * we wouldn't wait for EOF from slave pty
112 * (output may be produced by grandchildren of child) */
113 signal(SIGCHLD, record_signo);
114
115 /* TODO: SIGWINCH? pass window size changes down to slave? */
116
117 child_pid = xvfork();
118
119 if (child_pid) {
120 /* parent */
121 struct pollfd pfd[2];
122 int outfd, count, loop;
123 double oldtime = ENABLE_SCRIPTREPLAY ? time(NULL) : 0;
124 smallint fd_count = 2;
125#define buf bb_common_bufsiz1
126 setup_common_bufsiz();
127
128 outfd = xopen(fname, mode);
129 pfd[0].fd = pty;
130 pfd[0].events = POLLIN;
131 pfd[1].fd = STDIN_FILENO;
132 pfd[1].events = POLLIN;
133 ndelay_on(pty); /* this descriptor is not shared, can do this */
134 /* ndelay_on(STDIN_FILENO); - NO, stdin can be shared! Pity :( */
135
136 /* copy stdin to pty master input,
137 * copy pty master output to stdout and file */
138 /* TODO: don't use full_write's, use proper write buffering */
139 while (fd_count && !bb_got_signal) {
140 /* not safe_poll! we want SIGCHLD to EINTR poll */
141 if (poll(pfd, fd_count, -1) < 0 && errno != EINTR) {
142 /* If child exits too quickly, we may get EIO:
143 * for example, try "script -c true" */
144 break;
145 }
146 if (pfd[0].revents) {
147 errno = 0;
148 count = safe_read(pty, buf, COMMON_BUFSIZE);
149 if (count <= 0 && errno != EAGAIN) {
150 /* err/eof from pty: exit */
151 goto restore;
152 }
153 if (count > 0) {
154 if (ENABLE_SCRIPTREPLAY && (opt & OPT_t)) {
155 struct timeval tv;
156 double newtime;
157
158 gettimeofday(&tv, NULL);
159 newtime = tv.tv_sec + (double) tv.tv_usec / 1000000;
160 fprintf(stderr, "%f %u\n", newtime - oldtime, count);
161 oldtime = newtime;
162 }
163 full_write(STDOUT_FILENO, buf, count);
164 full_write(outfd, buf, count);
165 if (opt & OPT_f) {
166 fsync(outfd);
167 }
168 }
169 }
170 if (pfd[1].revents) {
171 count = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE);
172 if (count <= 0) {
173 /* err/eof from stdin: don't read stdin anymore */
174 pfd[1].revents = 0;
175 fd_count--;
176 } else {
177 full_write(pty, buf, count);
178 }
179 }
180 }
181 /* If loop was exited because SIGCHLD handler set bb_got_signal,
182 * there still can be some buffered output. But dont loop forever:
183 * we won't pump orphaned grandchildren's output indefinitely.
184 * Testcase: running this in script:
185 * exec dd if=/dev/zero bs=1M count=1
186 * must have "1+0 records in, 1+0 records out" captured too.
187 * (util-linux's script doesn't do this. buggy :) */
188 loop = 999;
189 /* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
190 while (--loop && (count = safe_read(pty, buf, COMMON_BUFSIZE)) > 0) {
191 full_write(STDOUT_FILENO, buf, count);
192 full_write(outfd, buf, count);
193 }
194 restore:
195 if (attr_ok == 0)
196 tcsetattr(0, TCSAFLUSH, &tt);
197 if (!(opt & OPT_q))
198 printf("Script done, file is %s\n", fname);
199 return EXIT_SUCCESS;
200 }
201
202 /* child: make pty slave to be input, output, error; run shell */
203 close(pty); /* close pty master */
204 /* open pty slave to fd 0,1,2 */
205 close(0);
206 xopen(pty_line, O_RDWR); /* uses fd 0 */
207 xdup2(0, 1);
208 xdup2(0, 2);
209 /* copy our original stdin tty's parameters to pty */
210 if (attr_ok == 0)
211 tcsetattr(0, TCSAFLUSH, &tt);
212 if (winsz_ok == 0)
213 ioctl(0, TIOCSWINSZ, (char *)&win);
214 /* set pty as a controlling tty */
215 setsid();
216 ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
217
218 /* Non-ignored signals revert to SIG_DFL on exec anyway */
219 /*signal(SIGCHLD, SIG_DFL);*/
220 execl(shell, shell, shell_opt, shell_arg, (char *) NULL);
221 bb_simple_perror_msg_and_die(shell);
222}
223
generated by cgit at 2024-05-15 05:54:19 (GMT)