xref: /freebsd/usr.bin/cmp/special.c (revision 783d3ff6d7fae619db8a7990b8a6387de0c677b5)
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 #include <sys/types.h>
33 
34 #include <capsicum_helpers.h>
35 #include <err.h>
36 #include <stdlib.h>
37 #include <stdio.h>
38 
39 #include "extern.h"
40 
41 void
42 c_special(int fd1, const char *file1, off_t skip1,
43     int fd2, const char *file2, off_t skip2, off_t limit)
44 {
45 	int ch1, ch2;
46 	off_t byte, line;
47 	FILE *fp1, *fp2;
48 	int dfound;
49 
50 	if (caph_limit_stream(fd1, CAPH_READ) < 0)
51 		err(ERR_EXIT, "caph_limit_stream(%s)", file1);
52 	if (caph_limit_stream(fd2, CAPH_READ) < 0)
53 		err(ERR_EXIT, "caph_limit_stream(%s)", file2);
54 	if (caph_enter() < 0)
55 		err(ERR_EXIT, "unable to enter capability mode");
56 
57 	if ((fp1 = fdopen(fd1, "r")) == NULL)
58 		err(ERR_EXIT, "%s", file1);
59 	(void)setvbuf(fp1, NULL, _IOFBF, 65536);
60 	if ((fp2 = fdopen(fd2, "r")) == NULL)
61 		err(ERR_EXIT, "%s", file2);
62 	(void)setvbuf(fp2, NULL, _IOFBF, 65536);
63 
64 	dfound = 0;
65 	while (skip1--)
66 		if (getc(fp1) == EOF)
67 			goto eof;
68 	while (skip2--)
69 		if (getc(fp2) == EOF)
70 			goto eof;
71 
72 	for (byte = line = 1; limit == 0 || byte <= limit; ++byte) {
73 #ifdef SIGINFO
74 		if (info) {
75 			(void)fprintf(stderr, "%s %s char %zu line %zu\n",
76 			    file1, file2, (size_t)byte, (size_t)line);
77 			info = 0;
78 		}
79 #endif
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 				if (bflag)
92 					(void)printf("%6lld %3o %c %3o %c\n",
93 					    (long long)byte, ch1, ch1, ch2,
94 					    ch2);
95 				else
96 					(void)printf("%6lld %3o %3o\n",
97 					    (long long)byte, ch1, ch2);
98 			} else {
99 				diffmsg(file1, file2, byte, line, ch1, ch2);
100 				/* NOTREACHED */
101 			}
102 		}
103 		if (ch1 == '\n')
104 			++line;
105 	}
106 
107 eof:	if (ferror(fp1))
108 		err(ERR_EXIT, "%s", file1);
109 	if (ferror(fp2))
110 		err(ERR_EXIT, "%s", file2);
111 	if (feof(fp1)) {
112 		if (!feof(fp2))
113 			eofmsg(file1);
114 	} else
115 		if (feof(fp2))
116 			eofmsg(file2);
117 	fclose(fp2);
118 	fclose(fp1);
119 	if (dfound)
120 		exit(DIFF_EXIT);
121 }
122