prettyness police

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

/*
* Copyright (c) 1987, 1990, 1993
*      The Regents of the University of California.  All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1987, 1990, 1993\n\
       The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)cmp.c       8.2 (Berkeley) %G%";
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>

#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "extern.h"

int     lflag, sflag;

static void usage __P((void));

int
main(argc, argv)
       int argc;
       char *argv[];
{
       struct stat sb1, sb2;
       off_t skip1, skip2;
       int ch, fd1, fd2, special;
       char *file1, *file2;

       while ((ch = getopt(argc, argv, "-ls")) != EOF)
               switch (ch) {
               case 'l':               /* print all differences */
                       lflag = 1;
                       break;
               case 's':               /* silent run */
                       sflag = 1;
                       break;
               case '-':               /* stdin (must be after options) */
                       --optind;
                       goto endargs;
               case '?':
               default:
                       usage();
               }
endargs:
       argv += optind;
       argc -= optind;

       if (lflag && sflag)
               errx(ERR_EXIT, "only one of -l and -s may be specified");

       if (argc < 2 || argc > 4)
               usage();

       /* Backward compatibility -- handle "-" meaning stdin. */
       special = 0;
       if (strcmp(file1 = argv[0], "-") == 0) {
               special = 1;
               fd1 = 0;
               file1 = "stdin";
       }
       else if ((fd1 = open(file1, O_RDONLY, 0)) < 0)
               err(ERR_EXIT, "%s", file1);
       if (strcmp(file2 = argv[1], "-") == 0) {
               if (special)
                       errx(ERR_EXIT,
                               "standard input may only be specified once");
               special = 1;
               fd2 = 0;
               file2 = "stdin";
       }
       else if ((fd2 = open(file2, O_RDONLY, 0)) < 0)
               err(ERR_EXIT, "%s", file2);

       skip1 = argc > 2 ? strtol(argv[2], NULL, 10) : 0;
       skip2 = argc == 4 ? strtol(argv[3], NULL, 10) : 0;

       if (!special) {
               if (fstat(fd1, &sb1))
                       err(ERR_EXIT, "%s", file1);
               if (!S_ISREG(sb1.st_mode))
                       special = 1;
               else {
                       if (fstat(fd2, &sb2))
                               err(ERR_EXIT, "%s", file2);
                       if (!S_ISREG(sb2.st_mode))
                               special = 1;
               }
       }

       if (special)
               c_special(fd1, file1, skip1, fd2, file2, skip2);
       else
               c_regular(fd1, file1, skip1, sb1.st_size,
                   fd2, file2, skip2, sb2.st_size);
       exit(0);
}

static void
usage()
{

       (void)fprintf(stderr,
           "usage: cmp [-l | s] file1 file2 [skip1 [skip2]]\n");
       exit(ERR_EXIT);
}