xref: /freebsd/usr.bin/cmp/regular.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
1 /*-
2  * Copyright (c) 1991, 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 sccsid[] = "@(#)regular.c	8.3 (Berkeley) 4/2/94";
36 #endif /* not lint */
37 
38 #include <sys/param.h>
39 #include <sys/mman.h>
40 #include <sys/stat.h>
41 
42 #include <err.h>
43 #include <limits.h>
44 #include <stdlib.h>
45 #include <stdio.h>
46 #include <string.h>
47 
48 #include "extern.h"
49 
50 void
51 c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
52 	int fd1, fd2;
53 	char *file1, *file2;
54 	off_t skip1, len1, skip2, len2;
55 {
56 	u_char ch, *p1, *p2;
57 	off_t byte, length, line;
58 	int dfound;
59 
60 	if (sflag && len1 != len2)
61 		exit(1);
62 
63 	if (skip1 > len1)
64 		eofmsg(file1);
65 	len1 -= skip1;
66 	if (skip2 > len2)
67 		eofmsg(file2);
68 	len2 -= skip2;
69 
70 	length = MIN(len1, len2);
71 	if (length > SIZE_T_MAX)
72 		return (c_special(fd1, file1, skip1, fd2, file2, skip2));
73 
74 	if ((p1 = (u_char *)mmap(NULL,
75 	    (size_t)length, PROT_READ, 0, fd1, skip1)) == (u_char *)-1)
76 		err(ERR_EXIT, "%s", file1);
77 	if ((p2 = (u_char *)mmap(NULL,
78 	    (size_t)length, PROT_READ, 0, fd2, skip2)) == (u_char *)-1)
79 		err(ERR_EXIT, "%s", file2);
80 
81 	dfound = 0;
82 	for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
83 		if ((ch = *p1) != *p2)
84 			if (lflag) {
85 				dfound = 1;
86 				(void)printf("%6qd %3o %3o\n", byte, ch, *p2);
87 			} else
88 				diffmsg(file1, file2, byte, line);
89 				/* NOTREACHED */
90 		if (ch == '\n')
91 			++line;
92 	}
93 
94 	if (len1 != len2)
95 		eofmsg (len1 > len2 ? file2 : file1);
96 	if (dfound)
97 		exit(DIFF_EXIT);
98 }
99