usr.bin/cmp/cmp.c

   1 /*
   2  * Copyright (c) 1987, 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * $FreeBSD: src/usr.bin/cmp/cmp.c,v 1.6.6.4 2001/11/21 10:47:54 dwmalone Exp $
  34  * $DragonFly: src/usr.bin/cmp/cmp.c,v 1.3 2003/10/02 17:42:27 hmp Exp $
  35  *
  36  * @(#) Copyright (c) 1987, 1990, 1993, 1994 The Regents of the University of California.  All rights reserved.
  37  * @(#)cmp.c    8.3 (Berkeley) 4/2/94
  38  */
  39
  40 #include <sys/types.h>
  41 #include <sys/stat.h>
  42
  43 #include <err.h>
  44 #include <fcntl.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 #include "extern.h"
  51
  52 int     lflag, sflag, xflag, zflag;
  53
  54 static void usage (void);
  55
  56 int
  57 main(int argc, char **argv)
  58 {
  59         struct stat sb1, sb2;
  60         off_t skip1, skip2;
  61         int ch, fd1, fd2, special;
  62         const char *file1, *file2;
  63
  64         while ((ch = getopt(argc, argv, "-lsxz")) != -1)
  65                 switch (ch) {
  66                 case 'l':               /* print all differences */
  67                         lflag = 1;
  68                         break;
  69                 case 's':               /* silent run */
  70                         sflag = 1;
  71                         zflag = 1;
  72                         break;
  73                 case 'x':               /* hex output */
  74                         lflag = 1;
  75                         xflag = 1;
  76                         break;
  77                 case 'z':               /* compare size first */
  78                         zflag = 1;
  79                         break;
  80                 case '-':               /* stdin (must be after options) */
  81                         --optind;
  82                         goto endargs;
  83                 case '?':
  84                 default:
  85                         usage();
  86                 }
  87 endargs:
  88         argv += optind;
  89         argc -= optind;
  90
  91         if (lflag && sflag)
  92                 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted");
  93
  94         if (argc < 2 || argc > 4)
  95                 usage();
  96
  97         /* Backward compatibility -- handle "-" meaning stdin. */
  98         special = 0;
  99         if (strcmp(file1 = argv[0], "-") == 0) {
 100                 special = 1;
 101                 fd1 = 0;
 102                 file1 = "stdin";
 103         }
 104         else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
 105                 if (!sflag)
 106                         err(ERR_EXIT, "%s", file1);
 107                 else
 108                         exit(1);
 109         }
 110         if (strcmp(file2 = argv[1], "-") == 0) {
 111                 if (special)
 112                         errx(ERR_EXIT,
 113                                 "standard input may only be specified once");
 114                 special = 1;
 115                 fd2 = 0;
 116                 file2 = "stdin";
 117         }
 118         else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
 119                 if (!sflag)
 120                         err(ERR_EXIT, "%s", file2);
 121                 else
 122                         exit(1);
 123         }
 124
 125         skip1 = argc > 2 ? strtol(argv[2], NULL, 0) : 0;
 126         skip2 = argc == 4 ? strtol(argv[3], NULL, 0) : 0;
 127
 128         if (!special) {
 129                 if (fstat(fd1, &sb1)) {
 130                         if (!sflag)
 131                                 err(ERR_EXIT, "%s", file1);
 132                         else
 133                                 exit(1);
 134                 }
 135                 if (!S_ISREG(sb1.st_mode))
 136                         special = 1;
 137                 else {
 138                         if (fstat(fd2, &sb2)) {
 139                                 if (!sflag)
 140                                         err(ERR_EXIT, "%s", file2);
 141                                 else
 142                                         exit(1);
 143                         }
 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                 if (zflag && sb1.st_size != sb2.st_size) {
 153                         if (!sflag)
 154                                 (void) printf("%s %s differ: size\n",
 155                                     file1, file2);
 156                         exit(DIFF_EXIT);
 157                 }
 158                 c_regular(fd1, file1, skip1, sb1.st_size,
 159                     fd2, file2, skip2, sb2.st_size);
 160         }
 161         exit(0);
 162 }
 163
 164 static void
 165 usage(void)
 166 {
 167
 168         (void)fprintf(stderr,
 169             "usage: cmp [-l | -s | -x] [-z] file1 file2 [skip1 [skip2]]\n");
 170         exit(ERR_EXIT);
 171 }