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cmp.c revision 1.13 
      1 /*	$NetBSD: cmp.c,v 1.13 2003/08/07 11:13:22 agc 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\n\
     35 	The Regents of the University of California.  All rights reserved.\n");
     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 1.13 2003/08/07 11:13:22 agc 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 <fcntl.h>
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <string.h>
     54 #include <unistd.h>
     55 #include <locale.h>
     56 
     57 #include "extern.h"
     58 
     59 int	lflag, sflag;
     60 
     61 int	main __P((int, char **));
     62 static void usage __P((void));
     63 
     64 int
     65 main(argc, argv)
     66 	int argc;
     67 	char *argv[];
     68 {
     69 	struct stat sb1, sb2;
     70 	off_t skip1, skip2;
     71 	int ch, fd1, fd2, special;
     72 	char *file1, *file2;
     73 
     74 	setlocale(LC_ALL, "");
     75 
     76 	while ((ch = getopt(argc, argv, "ls")) != -1)
     77 		switch (ch) {
     78 		case 'l':		/* print all differences */
     79 			lflag = 1;
     80 			break;
     81 		case 's':		/* silent run */
     82 			sflag = 1;
     83 			break;
     84 		case '?':
     85 		default:
     86 			usage();
     87 		}
     88 	argv += optind;
     89 	argc -= optind;
     90 
     91 	if (lflag && sflag)
     92 		errx(ERR_EXIT, "only one of -l and -s may be specified");
     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 			warn("%s", file1);
    107 		exit(ERR_EXIT);
    108 	}
    109 	if (strcmp(file2 = argv[1], "-") == 0) {
    110 		if (special)
    111 			errx(ERR_EXIT,
    112 				"standard input may only be specified once");
    113 		special = 1;
    114 		fd2 = 0;
    115 		file2 = "stdin";
    116 	}
    117 	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
    118 		if (!sflag)
    119 			warn("%s", file2);
    120 		exit(ERR_EXIT);
    121 	}
    122 
    123 	skip1 = argc > 2 ? strtoq(argv[2], NULL, 10) : 0;
    124 	skip2 = argc == 4 ? strtoq(argv[3], NULL, 10) : 0;
    125 
    126 	if (!special) {
    127 		if (fstat(fd1, &sb1))
    128 			err(ERR_EXIT, "%s", file1);
    129 		if (!S_ISREG(sb1.st_mode))
    130 			special = 1;
    131 		else {
    132 			if (fstat(fd2, &sb2))
    133 				err(ERR_EXIT, "%s", file2);
    134 			if (!S_ISREG(sb2.st_mode))
    135 				special = 1;
    136 		}
    137 	}
    138 
    139 	if (special)
    140 		c_special(fd1, file1, skip1, fd2, file2, skip2);
    141 	else
    142 		c_regular(fd1, file1, skip1, sb1.st_size,
    143 		    fd2, file2, skip2, sb2.st_size);
    144 	exit(0);
    145 }
    146 
    147 static void
    148 usage()
    149 {
    150 
    151 	(void)fprintf(stderr,
    152 	    "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n");
    153 	exit(ERR_EXIT);
    154 }
    155