1#include <unistd.h>
 2#include <errno.h>
 3#include <limits.h>
 4#include <string.h>
 5#include "syscall.h"
 6
 7char *getcwd(char *buf, size_t size)
 8{
 9	char tmp[buf ? 1 : PATH_MAX];
10	if (!buf) {
11		buf = tmp;
12		size = sizeof tmp;
13	} else if (!size) {
14		errno = EINVAL;
15		return 0;
16	}
17	long ret = syscall(SYS_getcwd, buf, size);
18	if (ret < 0)
19		return 0;
20	if (ret == 0 || buf[0] != '/') {
21		errno = ENOENT;
22		return 0;
23	}
24	return buf == tmp ? strdup(buf) : buf;
25}