1#define _GNU_SOURCE
 2#include <unistd.h>
 3#include <sys/utsname.h>
 4#include <string.h>
 5#include <errno.h>
 6
 7int getdomainname(char *name, size_t len)
 8{
 9	struct utsname temp;
10	uname(&temp);
11	if (!len || strlen(temp.domainname) >= len) {
12		errno = EINVAL;
13		return -1;
14	}
15	strcpy(name, temp.domainname);
16	return 0;
17}