1#include <stdlib.h>
 2#include <string.h>
 3#include <unistd.h>
 4#include <errno.h>
 5#include <limits.h>
 6
 7extern char **__environ;
 8
 9int __execvpe(const char *file, char *const argv[], char *const envp[])
10{
11	const char *p, *z, *path = getenv("PATH");
12	size_t l, k;
13	int seen_eacces = 0;
14
15	errno = ENOENT;
16	if (!*file) return -1;
17
18	if (strchr(file, '/'))
19		return execve(file, argv, envp);
20
21	if (!path) path = "/usr/local/bin:/bin:/usr/bin";
22	k = strnlen(file, NAME_MAX+1);
23	if (k > NAME_MAX) {
24		errno = ENAMETOOLONG;
25		return -1;
26	}
27	l = strnlen(path, PATH_MAX-1)+1;
28
29	for(p=path; ; p=z) {
30		char b[l+k+1];
31		z = __strchrnul(p, ':');
32		if (z-p >= l) {
33			if (!*z++) break;
34			continue;
35		}
36		memcpy(b, p, z-p);
37		b[z-p] = '/';
38		memcpy(b+(z-p)+(z>p), file, k+1);
39		execve(b, argv, envp);
40		switch (errno) {
41		case EACCES:
42			seen_eacces = 1;
43		case ENOENT:
44		case ENOTDIR:
45			break;
46		default:
47			return -1;
48		}
49		if (!*z++) break;
50	}
51	if (seen_eacces) errno = EACCES;
52	return -1;
53}
54
55int execvp(const char *file, char *const argv[])
56{
57	return __execvpe(file, argv, __environ);
58}
59
60weak_alias(__execvpe, execvpe);