usr.bin/cmp/cmp.c

   1 /*      $NetBSD: cmp.c,v 1.16 2008/07/21 14:19:21 lukem Exp $   */
   2
   3 /*
   4  * Copyright (c) 1987, 1990, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1987, 1990, 1993, 1994\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)cmp.c       8.3 (Berkeley) 4/2/94";
  41 #else
  42 __RCSID("$NetBSD: cmp.c,v 1.16 2008/07/21 14:19:21 lukem Exp $");
  43 #endif
  44 #endif /* not lint */
  45
  46 #include <sys/types.h>
  47 #include <sys/stat.h>
  48
  49 #include <err.h>
  50 #include <errno.h>
  51 #include <fcntl.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <string.h>
  55 #include <unistd.h>
  56 #include <locale.h>
  57
  58 #include "extern.h"
  59
  60 int     lflag, sflag;
  61
  62 static void usage(void);
  63
  64 int
  65 main(int argc, char *argv[])
  66 {
  67         struct stat sb1, sb2;
  68         off_t skip1 = 0, skip2 = 0;
  69         int ch, fd1, fd2, special;
  70         const char *file1, *file2;
  71
  72         setlocale(LC_ALL, "");
  73
  74         while ((ch = getopt(argc, argv, "ls")) != -1)
  75                 switch (ch) {
  76                 case 'l':               /* print all differences */
  77                         lflag = 1;
  78                         break;
  79                 case 's':               /* silent run */
  80                         sflag = 1;
  81                         break;
  82                 case '?':
  83                 default:
  84                         usage();
  85                 }
  86         argv += optind;
  87         argc -= optind;
  88
  89         if (lflag && sflag)
  90                 errx(ERR_EXIT, "only one of -l and -s may be specified");
  91
  92         if (argc < 2 || argc > 4)
  93                 usage();
  94
  95         /* Backward compatibility -- handle "-" meaning stdin. */
  96         special = 0;
  97         if (strcmp(file1 = argv[0], "-") == 0) {
  98                 special = 1;
  99                 fd1 = 0;
 100                 file1 = "stdin";
 101         }
 102         else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
 103                 if (!sflag)
 104                         warn("%s", file1);
 105                 exit(ERR_EXIT);
 106         }
 107         if (strcmp(file2 = argv[1], "-") == 0) {
 108                 if (special)
 109                         errx(ERR_EXIT,
 110                                 "standard input may only be specified once");
 111                 special = 1;
 112                 fd2 = 0;
 113                 file2 = "stdin";
 114         }
 115         else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
 116                 if (!sflag)
 117                         warn("%s", file2);
 118                 exit(ERR_EXIT);
 119         }
 120
 121         if (argc > 2) {
 122                 char *ep;
 123
 124                 errno = 0;
 125                 skip1 = strtoq(argv[2], &ep, 0);
 126                 if (errno || ep == argv[2])
 127                         usage();
 128
 129                 if (argc == 4) {
 130                         skip2 = strtoq(argv[3], &ep, 0);
 131                         if (errno || ep == argv[3])
 132                                 usage();
 133                 }
 134         }
 135
 136         if (!special) {
 137                 if (fstat(fd1, &sb1))
 138                         err(ERR_EXIT, "%s", file1);
 139                 if (!S_ISREG(sb1.st_mode))
 140                         special = 1;
 141                 else {
 142                         if (fstat(fd2, &sb2))
 143                                 err(ERR_EXIT, "%s", file2);
 144                         if (!S_ISREG(sb2.st_mode))
 145                                 special = 1;
 146                 }
 147         }
 148
 149         if (special)
 150                 c_special(fd1, file1, skip1, fd2, file2, skip2);
 151         else
 152                 c_regular(fd1, file1, skip1, sb1.st_size,
 153                     fd2, file2, skip2, sb2.st_size);
 154         exit(0);
 155 }
 156
 157 static void
 158 usage(void)
 159 {
 160
 161         (void)fprintf(stderr,
 162             "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n");
 163         exit(ERR_EXIT);
 164 }