busybox/libbb/execable.c

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 2006 Gabriel Somlo <somlo at cmu.edu>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"

/* check if path points to an executable file;
 * return 1 if found;
 * return 0 otherwise;
 */
int FAST_FUNC execable_file(const char *name)
{
	struct stat s;
	return (!access(name, X_OK) && !stat(name, &s) && S_ISREG(s.st_mode));
}

/* search (*PATHp) for an executable file;
 * return allocated string containing full path if found;
 *  PATHp points to the component after the one where it was found
 *  (or NULL),
 *  you may call find_execable again with this PATHp to continue
 *  (if it's not NULL).
 * return NULL otherwise; (PATHp is undefined)
 * in all cases (*PATHp) contents will be trashed (s/:/NUL/).
 */
char* FAST_FUNC find_execable(const char *filename, char **PATHp)
{
	char *p, *n;

	p = *PATHp;
	while (p) {
		n = strchr(p, ':');
		if (n)
			*n++ = '\0';
		if (*p != '\0') { /* it's not a PATH="foo::bar" situation */
			p = concat_path_file(p, filename);
			if (execable_file(p)) {
				*PATHp = n;
				return p;
			}
			free(p);
		}
		p = n;
	} /* on loop exit p == NULL */
	return p;
}

/* search $PATH for an executable file;
 * return 1 if found;
 * return 0 otherwise;
 */
int FAST_FUNC exists_execable(const char *filename)
{
	char *path = xstrdup(getenv("PATH"));
	char *tmp = path;
	char *ret = find_execable(filename, &tmp);
	free(path);
	if (ret) {
		free(ret);
		return 1;
	}
	return 0;
}

#if ENABLE_FEATURE_PREFER_APPLETS
/* just like the real execvp, but try to launch an applet named 'file' first
 */
int FAST_FUNC bb_execvp(const char *file, char *const argv[])
{
	return execvp(find_applet_by_name(file) >= 0 ? bb_busybox_exec_path : file,
					argv);
}
#endif
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	*/
16	int FAST_FUNC 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 (*PATHp) for an executable file;
23	* return allocated string containing full path if found;
24	* PATHp points to the component after the one where it was found
25	* (or NULL),
26	* you may call find_execable again with this PATHp to continue
27	* (if it's not NULL).
28	* return NULL otherwise; (PATHp is undefined)
29	* in all cases (*PATHp) contents will be trashed (s/:/NUL/).
30	*/
31	char* FAST_FUNC find_execable(const char filename, char *PATHp)
32	{
33	char p, n;
34
35	p = *PATHp;
36	while (p) {
37	n = strchr(p, ':');
38	if (n)
39	*n++ = '\0';
40	if (p != '\0') { / it's not a PATH="foo::bar" situation */
41	p = concat_path_file(p, filename);
42	if (execable_file(p)) {
43	*PATHp = n;
44	return p;
45	}
46	free(p);
47	}
48	p = n;
49	} /* on loop exit p == NULL */
50	return p;
51	}
52
53	/* search $PATH for an executable file;
54	* return 1 if found;
55	* return 0 otherwise;
56	*/
57	int FAST_FUNC exists_execable(const char *filename)
58	{
59	char *path = xstrdup(getenv("PATH"));
60	char *tmp = path;
61	char *ret = find_execable(filename, &tmp);
62	free(path);
63	if (ret) {
64	free(ret);
65	return 1;
66	}
67	return 0;
68	}
69
70	#if ENABLE_FEATURE_PREFER_APPLETS
71	/* just like the real execvp, but try to launch an applet named 'file' first
72	*/
73	int FAST_FUNC bb_execvp(const char file, char const argv[])
74	{
75	return execvp(find_applet_by_name(file) >= 0 ? bb_busybox_exec_path : file,
76	argv);
77	}
78	#endif