xref: /freebsd/usr.bin/cmp/special.c (revision 8a0a413e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1991, 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 #if 0
33 #ifndef lint
34 static char sccsid[] = "@(#)special.c	8.3 (Berkeley) 4/2/94";
35 #endif
36 #endif
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/types.h>
42 
43 #include <err.h>
44 #include <stdlib.h>
45 #include <stdio.h>
46 
47 #include "extern.h"
48 
49 void
50 c_special(int fd1, const char *file1, off_t skip1,
51     int fd2, const char *file2, off_t skip2)
52 {
53 	int ch1, ch2;
54 	off_t byte, line;
55 	FILE *fp1, *fp2;
56 	int dfound;
57 
58 	if ((fp1 = fdopen(fd1, "r")) == NULL)
59 		err(ERR_EXIT, "%s", file1);
60 	if ((fp2 = fdopen(fd2, "r")) == NULL)
61 		err(ERR_EXIT, "%s", file2);
62 
63 	dfound = 0;
64 	while (skip1--)
65 		if (getc(fp1) == EOF)
66 			goto eof;
67 	while (skip2--)
68 		if (getc(fp2) == EOF)
69 			goto eof;
70 
71 	for (byte = line = 1;; ++byte) {
72 		ch1 = getc(fp1);
73 		ch2 = getc(fp2);
74 		if (ch1 == EOF || ch2 == EOF)
75 			break;
76 		if (ch1 != ch2) {
77 			if (xflag) {
78 				dfound = 1;
79 				(void)printf("%08llx %02x %02x\n",
80 				    (long long)byte - 1, ch1, ch2);
81 			} else if (lflag) {
82 				dfound = 1;
83 				(void)printf("%6lld %3o %3o\n",
84 				    (long long)byte, ch1, ch2);
85 			} else {
86 				diffmsg(file1, file2, byte, line);
87 				/* NOTREACHED */
88 			}
89 		}
90 		if (ch1 == '\n')
91 			++line;
92 	}
93 
94 eof:	if (ferror(fp1))
95 		err(ERR_EXIT, "%s", file1);
96 	if (ferror(fp2))
97 		err(ERR_EXIT, "%s", file2);
98 	if (feof(fp1)) {
99 		if (!feof(fp2))
100 			eofmsg(file1);
101 	} else
102 		if (feof(fp2))
103 			eofmsg(file2);
104 	fclose(fp2);
105 	fclose(fp1);
106 	if (dfound)
107 		exit(DIFF_EXIT);
108 }
109