xref: /freebsd/usr.bin/cmp/special.c (revision 732a02b4e77866604a120a275c082bb6221bd2ff)
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 <capsicum_helpers.h>
44 #include <err.h>
45 #include <stdlib.h>
46 #include <stdio.h>
47 
48 #include "extern.h"
49 
50 void
51 c_special(int fd1, const char *file1, off_t skip1,
52     int fd2, const char *file2, off_t skip2)
53 {
54 	int ch1, ch2;
55 	off_t byte, line;
56 	FILE *fp1, *fp2;
57 	int dfound;
58 
59 	if (caph_limit_stream(fd1, CAPH_READ) < 0)
60 		err(ERR_EXIT, "caph_limit_stream(%s)", file1);
61 	if (caph_limit_stream(fd2, CAPH_READ) < 0)
62 		err(ERR_EXIT, "caph_limit_stream(%s)", file2);
63 	if (caph_enter() < 0)
64 		err(ERR_EXIT, "unable to enter capability mode");
65 
66 	if ((fp1 = fdopen(fd1, "r")) == NULL)
67 		err(ERR_EXIT, "%s", file1);
68 	if ((fp2 = fdopen(fd2, "r")) == NULL)
69 		err(ERR_EXIT, "%s", file2);
70 
71 	dfound = 0;
72 	while (skip1--)
73 		if (getc(fp1) == EOF)
74 			goto eof;
75 	while (skip2--)
76 		if (getc(fp2) == EOF)
77 			goto eof;
78 
79 	for (byte = line = 1;; ++byte) {
80 		ch1 = getc(fp1);
81 		ch2 = getc(fp2);
82 		if (ch1 == EOF || ch2 == EOF)
83 			break;
84 		if (ch1 != ch2) {
85 			if (xflag) {
86 				dfound = 1;
87 				(void)printf("%08llx %02x %02x\n",
88 				    (long long)byte - 1, ch1, ch2);
89 			} else if (lflag) {
90 				dfound = 1;
91 				(void)printf("%6lld %3o %3o\n",
92 				    (long long)byte, ch1, ch2);
93 			} else {
94 				diffmsg(file1, file2, byte, line);
95 				/* NOTREACHED */
96 			}
97 		}
98 		if (ch1 == '\n')
99 			++line;
100 	}
101 
102 eof:	if (ferror(fp1))
103 		err(ERR_EXIT, "%s", file1);
104 	if (ferror(fp2))
105 		err(ERR_EXIT, "%s", file2);
106 	if (feof(fp1)) {
107 		if (!feof(fp2))
108 			eofmsg(file1);
109 	} else
110 		if (feof(fp2))
111 			eofmsg(file2);
112 	fclose(fp2);
113 	fclose(fp1);
114 	if (dfound)
115 		exit(DIFF_EXIT);
116 }
117