xref: /freebsd-14.2/usr.bin/cmp/special.c (revision 02a8a4e4)
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 #include <sys/types.h>
40 
41 #include <capsicum_helpers.h>
42 #include <err.h>
43 #include <stdbool.h>
44 #include <stdlib.h>
45 #include <stdio.h>
46 
47 #include "extern.h"
48 
49 int
c_special(int fd1,const char * file1,off_t skip1,int fd2,const char * file2,off_t skip2,off_t limit)50 c_special(int fd1, const char *file1, off_t skip1,
51     int fd2, const char *file2, off_t skip2, off_t limit)
52 {
53 	int ch1, ch2;
54 	off_t byte, line;
55 	FILE *fp1, *fp2;
56 	int dfound;
57 
58 	if (caph_limit_stream(fd1, CAPH_READ) < 0)
59 		err(ERR_EXIT, "caph_limit_stream(%s)", file1);
60 	if (caph_limit_stream(fd2, CAPH_READ) < 0)
61 		err(ERR_EXIT, "caph_limit_stream(%s)", file2);
62 	if (caph_enter() < 0)
63 		err(ERR_EXIT, "unable to enter capability mode");
64 
65 	if ((fp1 = fdopen(fd1, "r")) == NULL)
66 		err(ERR_EXIT, "%s", file1);
67 	(void)setvbuf(fp1, NULL, _IOFBF, 65536);
68 	if ((fp2 = fdopen(fd2, "r")) == NULL)
69 		err(ERR_EXIT, "%s", file2);
70 	(void)setvbuf(fp2, NULL, _IOFBF, 65536);
71 
72 	dfound = 0;
73 	while (skip1--)
74 		if (getc(fp1) == EOF)
75 			goto eof;
76 	while (skip2--)
77 		if (getc(fp2) == EOF)
78 			goto eof;
79 
80 	for (byte = line = 1; limit == 0 || byte <= limit; ++byte) {
81 #ifdef SIGINFO
82 		if (info) {
83 			(void)fprintf(stderr, "%s %s char %zu line %zu\n",
84 			    file1, file2, (size_t)byte, (size_t)line);
85 			info = 0;
86 		}
87 #endif
88 		ch1 = getc(fp1);
89 		ch2 = getc(fp2);
90 		if (ch1 == EOF || ch2 == EOF)
91 			break;
92 		if (ch1 != ch2) {
93 			if (xflag) {
94 				dfound = 1;
95 				(void)printf("%08llx %02x %02x\n",
96 				    (long long)byte - 1, ch1, ch2);
97 			} else if (lflag) {
98 				dfound = 1;
99 				if (bflag)
100 					(void)printf("%6lld %3o %c %3o %c\n",
101 					    (long long)byte, ch1, ch1, ch2,
102 					    ch2);
103 				else
104 					(void)printf("%6lld %3o %3o\n",
105 					    (long long)byte, ch1, ch2);
106 			} else {
107 				diffmsg(file1, file2, byte, line, ch1, ch2);
108 				return (DIFF_EXIT);
109 			}
110 		}
111 		if (ch1 == '\n')
112 			++line;
113 	}
114 
115 eof:	if (ferror(fp1))
116 		err(ERR_EXIT, "%s", file1);
117 	if (ferror(fp2))
118 		err(ERR_EXIT, "%s", file2);
119 	if (feof(fp1)) {
120 		if (!feof(fp2)) {
121 			eofmsg(file1);
122 			return (DIFF_EXIT);
123 		}
124 	} else {
125 		if (feof(fp2)) {
126 			eofmsg(file2);
127 			return (DIFF_EXIT);
128 		}
129 	}
130 	fclose(fp2);
131 	fclose(fp1);
132 	return (dfound ? DIFF_EXIT : 0);
133 }
134