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 //config:config PWD
10 //config: bool "pwd (3.7 kb)"
11 //config: default y
12 //config: help
13 //config: pwd is used to print the current directory.
14
15 //applet:IF_PWD(APPLET_NOFORK(pwd, pwd, BB_DIR_BIN, BB_SUID_DROP, pwd))
16
17 //kbuild:lib-$(CONFIG_PWD) += pwd.o
18
19 //usage:#define pwd_trivial_usage
20 //usage: ""
21 //usage:#define pwd_full_usage "\n\n"
22 //usage: "Print the full filename of the current working directory"
23 //usage:
24 //usage:#define pwd_example_usage
25 //usage: "$ pwd\n"
26 //usage: "/root\n"
27
28 #include "libbb.h"
29
logical_getcwd(void)30 static int logical_getcwd(void)
31 {
32 struct stat st1;
33 struct stat st2;
34 char *wd;
35 char *p;
36
37 wd = getenv("PWD");
38 if (!wd || wd[0] != '/')
39 return 0;
40
41 p = wd;
42 while (*p) {
43 /* doing strstr(p, "/.") by hand is smaller and faster... */
44 if (*p++ != '/')
45 continue;
46 if (*p != '.')
47 continue;
48 /* we found "/.", skip to next char */
49 p++;
50 if (*p == '.')
51 p++; /* we found "/.." */
52 if (*p == '\0' || *p == '/')
53 return 0; /* "/./" or "/../" component: bad */
54 }
55
56 if (stat(wd, &st1) != 0)
57 return 0;
58 if (stat(".", &st2) != 0)
59 return 0;
60 if (st1.st_ino != st2.st_ino)
61 return 0;
62 if (st1.st_dev != st2.st_dev)
63 return 0;
64
65 puts(wd);
66 return 1;
67 }
68
69 int pwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
pwd_main(int argc UNUSED_PARAM,char ** argv UNUSED_PARAM)70 int pwd_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
71 {
72 char *buf;
73
74 if (ENABLE_DESKTOP) {
75 /* TODO: assume -L if $POSIXLY_CORRECT? (coreutils does that)
76 * Rationale:
77 * POSIX requires a default of -L, but most scripts expect -P
78 */
79 unsigned opt = getopt32(argv, "LP");
80 if ((opt & 1) && logical_getcwd())
81 return fflush_all();
82 }
83
84 buf = xrealloc_getcwd_or_warn(NULL);
85
86 if (buf) {
87 puts(buf);
88 free(buf);
89 return fflush_all();
90 }
91
92 return EXIT_FAILURE;
93 }
94