1 /* vi: set sw=4 ts=4: */
2 /*
3  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
4  * Copyright (C) 2006 Gabriel Somlo <somlo at cmu.edu>
5  *
6  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
7  */
8 //config:config WHICH
9 //config:	bool "which (3.8 kb)"
10 //config:	default y
11 //config:	help
12 //config:	which is used to find programs in your PATH and
13 //config:	print out their pathnames.
14 
15 //applet:IF_WHICH(APPLET_NOFORK(which, which, BB_DIR_USR_BIN, BB_SUID_DROP, which))
16 
17 //kbuild:lib-$(CONFIG_WHICH) += which.o
18 
19 //usage:#define which_trivial_usage
20 //usage:       "[-a] COMMAND..."
21 //usage:#define which_full_usage "\n\n"
22 //usage:       "Locate COMMAND\n"
23 //usage:     "\n	-a	Show all matches"
24 //usage:
25 //usage:#define which_example_usage
26 //usage:       "$ which login\n"
27 //usage:       "/bin/login\n"
28 
29 #include "libbb.h"
30 
31 int which_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
which_main(int argc UNUSED_PARAM,char ** argv)32 int which_main(int argc UNUSED_PARAM, char **argv)
33 {
34 	char *env_path;
35 	int status = 0;
36 	/* This sizeof(): bb_default_root_path is shorter than BB_PATH_ROOT_PATH */
37 	char buf[sizeof(BB_PATH_ROOT_PATH)];
38 
39 	env_path = getenv("PATH");
40 	if (!env_path)
41 		/* env_path must be writable, and must not alloc, so... */
42 		env_path = strcpy(buf, bb_default_root_path);
43 
44 	getopt32(argv, "^" "a" "\0" "-1"/*at least one arg*/);
45 	argv += optind;
46 
47 	do {
48 		int missing = 1;
49 
50 		/* If file contains a slash don't use PATH */
51 		if (strchr(*argv, '/')) {
52 			if (file_is_executable(*argv)) {
53 				missing = 0;
54 				puts(*argv);
55 			}
56 		} else {
57 			char *path;
58 			char *p;
59 
60 			path = env_path;
61 			/* NOFORK NB: xmalloc inside find_executable(), must have no allocs above! */
62 			while ((p = find_executable(*argv, &path)) != NULL) {
63 				missing = 0;
64 				puts(p);
65 				free(p);
66 				if (!option_mask32) /* -a not set */
67 					break;
68 			}
69 		}
70 		status |= missing;
71 	} while (*++argv);
72 
73 	return status;
74 }
75