Home | History | Annotate | Line # | Download | only in cmp
cmp.c revision 1.14 
      1 /*	$NetBSD: cmp.c,v 1.14 2005/02/06 20:50:34 dsl 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 1.14 2005/02/06 20:50:34 dsl 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 static void usage(void);
     62 
     63 int
     64 main(int argc, char *argv[])
     65 {
     66 	struct stat sb1, sb2;
     67 	off_t skip1, skip2;
     68 	int ch, fd1, fd2, special;
     69 	char *file1, *file2;
     70 
     71 	setlocale(LC_ALL, "");
     72 
     73 	while ((ch = getopt(argc, argv, "ls")) != -1)
     74 		switch (ch) {
     75 		case 'l':		/* print all differences */
     76 			lflag = 1;
     77 			break;
     78 		case 's':		/* silent run */
     79 			sflag = 1;
     80 			break;
     81 		case '?':
     82 		default:
     83 			usage();
     84 		}
     85 	argv += optind;
     86 	argc -= optind;
     87 
     88 	if (lflag && sflag)
     89 		errx(ERR_EXIT, "only one of -l and -s may be specified");
     90 
     91 	if (argc < 2 || argc > 4)
     92 		usage();
     93 
     94 	/* Backward compatibility -- handle "-" meaning stdin. */
     95 	special = 0;
     96 	if (strcmp(file1 = argv[0], "-") == 0) {
     97 		special = 1;
     98 		fd1 = 0;
     99 		file1 = "stdin";
    100 	}
    101 	else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
    102 		if (!sflag)
    103 			warn("%s", file1);
    104 		exit(ERR_EXIT);
    105 	}
    106 	if (strcmp(file2 = argv[1], "-") == 0) {
    107 		if (special)
    108 			errx(ERR_EXIT,
    109 				"standard input may only be specified once");
    110 		special = 1;
    111 		fd2 = 0;
    112 		file2 = "stdin";
    113 	}
    114 	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
    115 		if (!sflag)
    116 			warn("%s", file2);
    117 		exit(ERR_EXIT);
    118 	}
    119 
    120 	skip1 = argc > 2 ? strtoq(argv[2], NULL, 10) : 0;
    121 	skip2 = argc == 4 ? strtoq(argv[3], NULL, 10) : 0;
    122 
    123 	if (!special) {
    124 		if (fstat(fd1, &sb1))
    125 			err(ERR_EXIT, "%s", file1);
    126 		if (!S_ISREG(sb1.st_mode))
    127 			special = 1;
    128 		else {
    129 			if (fstat(fd2, &sb2))
    130 				err(ERR_EXIT, "%s", file2);
    131 			if (!S_ISREG(sb2.st_mode))
    132 				special = 1;
    133 		}
    134 	}
    135 
    136 	if (special)
    137 		c_special(fd1, file1, skip1, fd2, file2, skip2);
    138 	else
    139 		c_regular(fd1, file1, skip1, sb1.st_size,
    140 		    fd2, file2, skip2, sb2.st_size);
    141 	exit(0);
    142 }
    143 
    144 static void
    145 usage(void)
    146 {
    147 
    148 	(void)fprintf(stderr,
    149 	    "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n");
    150 	exit(ERR_EXIT);
    151 }
    152