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