uclibc-ng/libc/stdlib/mktemp.c

#include <string.h>
#include <features.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>

char * mktemp(template)
char * template;
{
	int i;
	int num __attribute__ ((unused)); /* UNINITIALIZED */
	int n2;
	int l = strlen(template);
	struct stat stbuf;
	
	if (l<6) {
		errno = EINVAL;
		return 0;
	}
	
	for(i=l-6;i<l;i++)
		if (template[i] != 'X') {
			errno = EINVAL;
			return 0;
		}
	
again:	
	n2 = num;
	for(i=l-1;i>=l-6;i--) {
		template[i] = '0' + n2 % 10;
		n2 /= 10;
	}
	
	if (stat(template, &stbuf) == 0) {
		num++;
		goto again;
	}
	
	return template;
}