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cmp.c revision 1.10 
      1 /*	$NetBSD: cmp.c,v 1.10 1997/10/18 12:52:11 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __COPYRIGHT("@(#) Copyright (c) 1987, 1990, 1993, 1994\n\
     39 	The Regents of the University of California.  All rights reserved.\n");
     40 #endif /* not lint */
     41 
     42 #ifndef lint
     43 #if 0
     44 static char sccsid[] = "@(#)cmp.c	8.3 (Berkeley) 4/2/94";
     45 #else
     46 __RCSID("$NetBSD: cmp.c,v 1.10 1997/10/18 12:52:11 lukem Exp $");
     47 #endif
     48 #endif /* not lint */
     49 
     50 #include <sys/types.h>
     51 #include <sys/stat.h>
     52 
     53 #include <err.h>
     54 #include <fcntl.h>
     55 #include <stdio.h>
     56 #include <stdlib.h>
     57 #include <string.h>
     58 #include <unistd.h>
     59 #include <locale.h>
     60 
     61 #include "extern.h"
     62 
     63 int	lflag, sflag;
     64 
     65 int	main __P((int, char **));
     66 static void usage __P((void));
     67 
     68 int
     69 main(argc, argv)
     70 	int argc;
     71 	char *argv[];
     72 {
     73 	struct stat sb1, sb2;
     74 	off_t skip1, skip2;
     75 	int ch, fd1, fd2, special;
     76 	char *file1, *file2;
     77 
     78 	setlocale(LC_ALL, "");
     79 
     80 	while ((ch = getopt(argc, argv, "ls")) != EOF)
     81 		switch (ch) {
     82 		case 'l':		/* print all differences */
     83 			lflag = 1;
     84 			break;
     85 		case 's':		/* silent run */
     86 			sflag = 1;
     87 			break;
     88 		case '?':
     89 		default:
     90 			usage();
     91 		}
     92 	argv += optind;
     93 	argc -= optind;
     94 
     95 	if (lflag && sflag)
     96 		errx(ERR_EXIT, "only one of -l and -s may be specified");
     97 
     98 	if (argc < 2 || argc > 4)
     99 		usage();
    100 
    101 	/* Backward compatibility -- handle "-" meaning stdin. */
    102 	special = 0;
    103 	if (strcmp(file1 = argv[0], "-") == 0) {
    104 		special = 1;
    105 		fd1 = 0;
    106 		file1 = "stdin";
    107 	}
    108 	else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
    109 		if (!sflag)
    110 			warn("%s", file1);
    111 		exit(ERR_EXIT);
    112 	}
    113 	if (strcmp(file2 = argv[1], "-") == 0) {
    114 		if (special)
    115 			errx(ERR_EXIT,
    116 				"standard input may only be specified once");
    117 		special = 1;
    118 		fd2 = 0;
    119 		file2 = "stdin";
    120 	}
    121 	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
    122 		if (!sflag)
    123 			warn("%s", file2);
    124 		exit(ERR_EXIT);
    125 	}
    126 
    127 	skip1 = argc > 2 ? strtoq(argv[2], NULL, 10) : 0;
    128 	skip2 = argc == 4 ? strtoq(argv[3], NULL, 10) : 0;
    129 
    130 	if (!special) {
    131 		if (fstat(fd1, &sb1))
    132 			err(ERR_EXIT, "%s", file1);
    133 		if (!S_ISREG(sb1.st_mode))
    134 			special = 1;
    135 		else {
    136 			if (fstat(fd2, &sb2))
    137 				err(ERR_EXIT, "%s", file2);
    138 			if (!S_ISREG(sb2.st_mode))
    139 				special = 1;
    140 		}
    141 	}
    142 
    143 	if (special)
    144 		c_special(fd1, file1, skip1, fd2, file2, skip2);
    145 	else
    146 		c_regular(fd1, file1, skip1, sb1.st_size,
    147 		    fd2, file2, skip2, sb2.st_size);
    148 	exit(0);
    149 }
    150 
    151 static void
    152 usage()
    153 {
    154 
    155 	(void)fprintf(stderr,
    156 	    "usage: cmp [-l | s] file1 file2 [skip1 [skip2]]\n");
    157 	exit(ERR_EXIT);
    158 }
    159