Check if a string match a (bcrypt) hash

/* 
 * Description: Check if a hash match a string 
 * Version:  0.1
 * Licence:  MIT
 * Author:  Xavier Cartron prx@si3t.ch
 */

#include <err.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <pwd.h>
#include <unistd.h>

/* compare password passed on stdin with hash passed as argv[2] */

int 
main(int argc, char *argv[])
{

	char pw[LINE_MAX] = {'\0'};

	if (argc != 2)
		errx(1, "usage: printf \"pw\" | %s <hash>", argv[0]);

	if (fgets(pw, LINE_MAX, stdin) == NULL)
		err(1, "fail to read from stdin");
	pw[strcspn(pw, "\n")] = '\0'; /* remove ending \n if any */

	if (crypt_checkpass(pw, argv[1]) != 0)
		return 1;

	printf("match \\o/\n");
	return 0;
}