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cmp.c revision 1.1.1.2 
      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 
     34 #ifndef lint
     35 static char copyright[] =
     36 "@(#) Copyright (c) 1987, 1990, 1993, 1994\n\
     37 	The Regents of the University of California.  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 static char sccsid[] = "@(#)cmp.c	8.3 (Berkeley) 4/2/94";
     42 #endif /* not lint */
     43 
     44 #include <sys/types.h>
     45 #include <sys/stat.h>
     46 
     47 #include <err.h>
     48 #include <fcntl.h>
     49 #include <stdio.h>
     50 #include <stdlib.h>
     51 #include <string.h>
     52 #include <unistd.h>
     53 
     54 #include "extern.h"
     55 
     56 int	lflag, sflag;
     57 
     58 static void usage __P((void));
     59 
     60 int
     61 main(argc, argv)
     62 	int argc;
     63 	char *argv[];
     64 {
     65 	struct stat sb1, sb2;
     66 	off_t skip1, skip2;
     67 	int ch, fd1, fd2, special;
     68 	char *file1, *file2;
     69 
     70 	while ((ch = getopt(argc, argv, "-ls")) != EOF)
     71 		switch (ch) {
     72 		case 'l':		/* print all differences */
     73 			lflag = 1;
     74 			break;
     75 		case 's':		/* silent run */
     76 			sflag = 1;
     77 			break;
     78 		case '-':		/* stdin (must be after options) */
     79 			--optind;
     80 			goto endargs;
     81 		case '?':
     82 		default:
     83 			usage();
     84 		}
     85 endargs:
     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 		err(ERR_EXIT, "%s", file1);
    104 	if (strcmp(file2 = argv[1], "-") == 0) {
    105 		if (special)
    106 			errx(ERR_EXIT,
    107 				"standard input may only be specified once");
    108 		special = 1;
    109 		fd2 = 0;
    110 		file2 = "stdin";
    111 	}
    112 	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0)
    113 		err(ERR_EXIT, "%s", file2);
    114 
    115 	skip1 = argc > 2 ? strtol(argv[2], NULL, 10) : 0;
    116 	skip2 = argc == 4 ? strtol(argv[3], NULL, 10) : 0;
    117 
    118 	if (!special) {
    119 		if (fstat(fd1, &sb1))
    120 			err(ERR_EXIT, "%s", file1);
    121 		if (!S_ISREG(sb1.st_mode))
    122 			special = 1;
    123 		else {
    124 			if (fstat(fd2, &sb2))
    125 				err(ERR_EXIT, "%s", file2);
    126 			if (!S_ISREG(sb2.st_mode))
    127 				special = 1;
    128 		}
    129 	}
    130 
    131 	if (special)
    132 		c_special(fd1, file1, skip1, fd2, file2, skip2);
    133 	else
    134 		c_regular(fd1, file1, skip1, sb1.st_size,
    135 		    fd2, file2, skip2, sb2.st_size);
    136 	exit(0);
    137 }
    138 
    139 static void
    140 usage()
    141 {
    142 
    143 	(void)fprintf(stderr,
    144 	    "usage: cmp [-l | s] file1 file2 [skip1 [skip2]]\n");
    145 	exit(ERR_EXIT);
    146 }
    147