date and time created 91/10/27 14:14:54 by bostic

[unix-history] / usr / src / usr.bin / cmp / regular.c

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char sccsid[] = "@(#)regular.c   5.1 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "extern.h"

void
c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
       int fd1, fd2;
       char *file1, *file2;
       off_t skip1, len1, skip2, len2;
{
       register u_char ch, *p1, *p2;
       register off_t byte, length, line;
       int dfound;

       if (sflag && len1 != len2)
               exit(1);

       if (skip1 >= len1)
               eofmsg(file1);
       len1 -= skip1;
       if (skip2 >= len2)
               eofmsg(file2);
       len2 -= skip2;

       length = MIN(len1, len2);
       if ((p1 = (u_char *)mmap(NULL,
           length, PROT_READ, MAP_FILE, fd1, skip1)) == (u_char *)-1)
               err("%s: %s", file1, strerror(errno));
       if ((p2 = (u_char *)mmap(NULL,
           length, PROT_READ, MAP_FILE, fd2, skip2)) == (u_char *)-1)
               err("%s: %s", file2, strerror(errno));

       dfound = 0;
       for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
               if ((ch = *p1) != *p2)
                       if (lflag) {
                               dfound = 1;
                               (void)printf("%6ld %3o %3o\n", byte, ch, *p2);
                       } else
                               diffmsg(file1, file2, byte, line);
                               /* NOTREACHED */
               if (ch == '\n')
                       ++line;
       }

       if (len1 != len2)
               eofmsg (len1 > len2 ? file2 : file1);
       if (dfound)
               exit(1);
}