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cmp.c revision 1.16 
      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 	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 }
    165