xref: /freebsd/usr.bin/cmp/special.c (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
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, off_t limit)
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 	(void)setvbuf(fp1, NULL, _IOFBF, 65536);
69 	if ((fp2 = fdopen(fd2, "r")) == NULL)
70 		err(ERR_EXIT, "%s", file2);
71 	(void)setvbuf(fp2, NULL, _IOFBF, 65536);
72 
73 	dfound = 0;
74 	while (skip1--)
75 		if (getc(fp1) == EOF)
76 			goto eof;
77 	while (skip2--)
78 		if (getc(fp2) == EOF)
79 			goto eof;
80 
81 	for (byte = line = 1; limit == 0 || byte <= limit; ++byte) {
82 #ifdef SIGINFO
83 		if (info) {
84 			(void)fprintf(stderr, "%s %s char %zu line %zu\n",
85 			    file1, file2, (size_t)byte, (size_t)line);
86 			info = 0;
87 		}
88 #endif
89 		ch1 = getc(fp1);
90 		ch2 = getc(fp2);
91 		if (ch1 == EOF || ch2 == EOF)
92 			break;
93 		if (ch1 != ch2) {
94 			if (xflag) {
95 				dfound = 1;
96 				(void)printf("%08llx %02x %02x\n",
97 				    (long long)byte - 1, ch1, ch2);
98 			} else if (lflag) {
99 				dfound = 1;
100 				if (bflag)
101 					(void)printf("%6lld %3o %c %3o %c\n",
102 					    (long long)byte, ch1, ch1, ch2,
103 					    ch2);
104 				else
105 					(void)printf("%6lld %3o %3o\n",
106 					    (long long)byte, ch1, ch2);
107 			} else {
108 				diffmsg(file1, file2, byte, line, ch1, ch2);
109 				/* NOTREACHED */
110 			}
111 		}
112 		if (ch1 == '\n')
113 			++line;
114 	}
115 
116 eof:	if (ferror(fp1))
117 		err(ERR_EXIT, "%s", file1);
118 	if (ferror(fp2))
119 		err(ERR_EXIT, "%s", file2);
120 	if (feof(fp1)) {
121 		if (!feof(fp2))
122 			eofmsg(file1);
123 	} else
124 		if (feof(fp2))
125 			eofmsg(file2);
126 	fclose(fp2);
127 	fclose(fp1);
128 	if (dfound)
129 		exit(DIFF_EXIT);
130 }
131