blob: bb3ad04fc0bfaed6e840e1011d9167a4e5c433db
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini pwd implementation for busybox |
4 | * |
5 | * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. |
6 | * |
7 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
8 | */ |
9 | |
10 | //usage:#define pwd_trivial_usage |
11 | //usage: "" |
12 | //usage:#define pwd_full_usage "\n\n" |
13 | //usage: "Print the full filename of the current working directory" |
14 | //usage: |
15 | //usage:#define pwd_example_usage |
16 | //usage: "$ pwd\n" |
17 | //usage: "/root\n" |
18 | |
19 | #include "libbb.h" |
20 | |
21 | /* This is a NOFORK applet. Be very careful! */ |
22 | |
23 | static int logical_getcwd(void) |
24 | { |
25 | struct stat st1; |
26 | struct stat st2; |
27 | char *wd; |
28 | char *p; |
29 | |
30 | wd = getenv("PWD"); |
31 | if (!wd || wd[0] != '/') |
32 | return 0; |
33 | |
34 | p = wd; |
35 | while (*p) { |
36 | /* doing strstr(p, "/.") by hand is smaller and faster... */ |
37 | if (*p++ != '/') |
38 | continue; |
39 | if (*p != '.') |
40 | continue; |
41 | /* we found "/.", skip to next char */ |
42 | p++; |
43 | if (*p == '.') |
44 | p++; /* we found "/.." */ |
45 | if (*p == '\0' || *p == '/') |
46 | return 0; /* "/./" or "/../" component: bad */ |
47 | } |
48 | |
49 | if (stat(wd, &st1) != 0) |
50 | return 0; |
51 | if (stat(".", &st2) != 0) |
52 | return 0; |
53 | if (st1.st_ino != st2.st_ino) |
54 | return 0; |
55 | if (st1.st_dev != st2.st_dev) |
56 | return 0; |
57 | |
58 | puts(wd); |
59 | return 1; |
60 | } |
61 | |
62 | int pwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
63 | int pwd_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) |
64 | { |
65 | char *buf; |
66 | |
67 | if (ENABLE_DESKTOP) { |
68 | /* TODO: assume -L if $POSIXLY_CORRECT? (coreutils does that) |
69 | * Rationale: |
70 | * POSIX requires a default of -L, but most scripts expect -P |
71 | */ |
72 | unsigned opt = getopt32(argv, "LP"); |
73 | if ((opt & 1) && logical_getcwd()) |
74 | return fflush_all(); |
75 | } |
76 | |
77 | buf = xrealloc_getcwd_or_warn(NULL); |
78 | |
79 | if (buf) { |
80 | puts(buf); |
81 | free(buf); |
82 | return fflush_all(); |
83 | } |
84 | |
85 | return EXIT_FAILURE; |
86 | } |
87 |