+}
+
+int compare(FILE *f1, FILE *f2)
+{
+ int l = 0, n = 0;
+ char b1[1024], b2[1024];
+ char *s1, *s2;
+
+ for(;;) {
+ l++;
+ s1 = fgets(b1, sizeof b1, f1);
+ s2 = fgets(b2, sizeof b2, f2);
+ if (s1 == NULL || s2 == NULL) {
+ if (s1 != s2) {
+ fprintf(stderr, "Length of outputs differ\n");
+ n++;
+ }
+ return n;
+ }
+ if (strcmp(s1, s2)) {
+ fprintf(stderr, "Line %d differ\n\t%s\t%s", l, s1, s2);
+ n++;
+ }
+ }
+}
+
+int main(int ac, char **av)
+{
+ FILE *in = stdin;
+ FILE *out = stdout;
+ FILE *ref = NULL;
+
+ if (ac >= 2) {
+ in = fopen(av[1], "r");
+ if (in == NULL) {
+ fprintf(stderr, "Can't open file %s: %m\n", av[1]);
+ return 1;
+ }
+ }
+
+ if (ac < 3)
+ setvbuf(stdout, NULL, _IOLBF, 0);
+ else {
+ ref = fopen(av[2], "r");
+ if (ref == NULL) {
+ fprintf(stderr, "Can't open file %s: %m\n", av[2]);
+ return 1;
+ }
+ out = tmpfile();
+ if (out == NULL) {
+ fprintf(stderr, "Can't create temporary file: %m\n");
+ return 1;
+ }
+ }
+
+ process(in, out);
+
+ if (ref) {
+ rewind(out);
+ if (compare(out, ref))
+ return 1;
+ }
+