/* diff.c  09-Jan-89  A.J.Travis */

/*
 * 'line by line' file comparison
 */

#include <stdio.h>

#define SAME 0

FILE *fp1, *fp2;
char *bp1, *bp2;
int c1, c2;
int eof1, eof2;
int n;
char buf1[BUFSIZ];
char buf2[BUFSIZ];

int main(argc, argv)
int argc;
char *argv[];
{
	if (argc != 3) {
		fprintf(stderr, "usage: diff file1 file2\n");
		exit(-1);
	}
	if ((fp1 = fopen(argv[1], "r")) == NULL) {
		fprintf(stderr, "diff: can't open %s\n", argv[1]);
		exit(-1);
	}
	if ((fp2 = fopen(argv[2], "r")) == NULL) {
		fprintf(stderr, "diff: can't open %s\n", argv[2]);
		fclose(fp1);
		exit(-1);
	}
	n = 0;
	while (++n) {
		eof1 = (fgets(buf1, BUFSIZ, fp1) == NULL);
		eof2 = (fgets(buf2, BUFSIZ, fp2) == NULL);
		if (eof1 & eof2)
			break;
		if (eof1 & (eof2 == 0)) {
			printf("diff: end of file on %s\n", argv[1]);
			break;
		}
		if (eof2 & (eof1 == 0)) {
			printf("diff: end of file on %s\n", argv[2]);
			break;
		}
		if (strcmp(buf1, buf2) != SAME)
			printf("%d:\n< %s> %s", n, buf1, buf2);
	}
	fclose(fp1);
	fclose(fp2);
	exit(0);
}