1#include <stdio.h>
2#include <fcntl.h>
3#include <errno.h>
4#include <sys/stat.h>
5#include <limits.h>
6#include <string.h>
7#include "syscall.h"
8
9#define MAXTRIES 100
10
11char *__randname(char *);
12
13char *tempnam(const char *dir, const char *pfx)
14{
15	char s[PATH_MAX];
16	size_t l, dl, pl;
17	int try;
18	int r;
19
20	if (!dir) dir = P_tmpdir;
21	if (!pfx) pfx = "temp";
22
23	dl = strlen(dir);
24	pl = strlen(pfx);
25	l = dl + 1 + pl + 1 + 6;
26
27	if (l >= PATH_MAX) {
28		errno = ENAMETOOLONG;
29		return 0;
30	}
31
32	memcpy(s, dir, dl);
33	s[dl] = '/';
34	memcpy(s+dl+1, pfx, pl);
35	s[dl+1+pl] = '_';
36	s[l] = 0;
37
38	for (try=0; try<MAXTRIES; try++) {
39		__randname(s+l-6);
40#ifdef SYS_lstat
41		r = __syscall(SYS_lstat, s, &(struct stat){0});
42#else
43		r = __syscall(SYS_fstatat, AT_FDCWD, s,
44			&(struct stat){0}, AT_SYMLINK_NOFOLLOW);
45#endif
46		if (r == -ENOENT) return strdup(s);
47	}
48	return 0;
49}
50