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