summaryrefslogtreecommitdiff
path: root/src/process/execvp.c
blob: 7d32200395ba72c4d88b511589c7995a03689ba8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <limits.h>
#include "libc.h"

extern char **__environ;

int __execvpe(const char *file, char *const argv[], char *const envp[])
{
	const char *p, *z, *path = getenv("PATH");
	size_t l, k;

	errno = ENOENT;
	if (!*file) return -1;

	if (strchr(file, '/'))
		return execve(file, argv, envp);

	if (!path) path = "/usr/local/bin:/bin:/usr/bin";
	k = strnlen(file, NAME_MAX+1);
	if (k > NAME_MAX) {
		errno = ENAMETOOLONG;
		return -1;
	}
	l = strnlen(path, PATH_MAX-1)+1;

	for(p=path; ; p=z) {
		char b[l+k+1];
		z = strchr(p, ':');
		if (!z) z = p+strlen(p);
		if (z-p >= l) {
			if (!*z++) break;
			continue;
		}
		memcpy(b, p, z-p);
		b[z-p] = '/';
		memcpy(b+(z-p)+(z>p), file, k+1);
		execve(b, argv, envp);
		if (errno != ENOENT) return -1;
		if (!*z++) break;
	}
	return -1;
}

int execvp(const char *file, char *const argv[])
{
	return __execvpe(file, argv, __environ);
}

weak_alias(__execvpe, execvpe);