1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) 2006 Gabriel Somlo <somlo at cmu.edu>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include "libbb.h"
11
12/* check if path points to an executable file;
13 * return 1 if found;
14 * return 0 otherwise;
15 */
16int execable_file(const char *name)
17{
18	struct stat s;
19	return (!access(name, X_OK) && !stat(name, &s) && S_ISREG(s.st_mode));
20}
21
22/* search $PATH for an executable file;
23 * return allocated string containing full path if found;
24 * return NULL otherwise;
25 */
26char *find_execable(const char *filename)
27{
28	char *path, *p, *n;
29
30	p = path = xstrdup(getenv("PATH"));
31	while (p) {
32		n = strchr(p, ':');
33		if (n)
34			*n++ = '\0';
35		if (*p != '\0') { /* it's not a PATH="foo::bar" situation */
36			p = concat_path_file(p, filename);
37			if (execable_file(p)) {
38				free(path);
39				return p;
40			}
41			free(p);
42		}
43		p = n;
44	}
45	free(path);
46	return NULL;
47}
48
49/* search $PATH for an executable file;
50 * return 1 if found;
51 * return 0 otherwise;
52 */
53int exists_execable(const char *filename)
54{
55	char *ret = find_execable(filename);
56	if (ret) {
57		free(ret);
58		return 1;
59	}
60	return 0;
61}
62
63#if ENABLE_FEATURE_PREFER_APPLETS
64/* just like the real execvp, but try to launch an applet named 'file' first
65 */
66int bb_execvp(const char *file, char *const argv[])
67{
68	return execvp(find_applet_by_name(file) ? bb_busybox_exec_path : file,
69					argv);
70}
71#endif
72