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authornobody <nobody@localhost>2004-10-13 09:42:10 +0000
committernobody <nobody@localhost>2004-10-13 09:42:10 +0000
commit8c59a0bf0e9e2d87b0ff273ea3f0bf05bbbf6373 (patch)
tree1826706cd4fd009fcd14f4f8021005ec8ec0fa59 /busybox/coreutils/cmp.c
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This commit was manufactured by cvs2svn to create tag 'busybox_1_00'.
Diffstat (limited to 'busybox/coreutils/cmp.c')
-rw-r--r--busybox/coreutils/cmp.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/busybox/coreutils/cmp.c b/busybox/coreutils/cmp.c
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1/* vi: set sw=4 ts=4: */
2/*
3 * Mini cmp implementation for busybox
4 *
5 * Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 */
22
23/* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */
24/* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */
25
26/* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
27 *
28 * Original version majorly reworked for SUSv3 compliance, bug fixes, and
29 * size optimizations. Changes include:
30 * 1) Now correctly distinguishes between errors and actual file differences.
31 * 2) Proper handling of '-' args.
32 * 3) Actual error checking of i/o.
33 * 4) Accept SUSv3 -l option. Note that we use the slightly nicer gnu format
34 * in the '-l' case.
35 */
36
37#include <stdio.h>
38#include <stdlib.h>
39#include <unistd.h>
40#include "busybox.h"
41
42static FILE *cmp_xfopen_input(const char *filename)
43{
44 FILE *fp;
45
46 if ((fp = bb_wfopen_input(filename)) != NULL) {
47 return fp;
48 }
49
50 exit(bb_default_error_retval); /* We already output an error message. */
51}
52
53static const char fmt_eof[] = "cmp: EOF on %s\n";
54static const char fmt_differ[] = "%s %s differ: char %d, line %d\n";
55#if 0
56static const char fmt_l_opt[] = "%.0s%.0s%d %o %o\n"; /* SUSv3 format */
57#else
58static const char fmt_l_opt[] = "%.0s%.0s%d %3o %3o\n"; /* nicer gnu format */
59#endif
60
61static const char opt_chars[] = "sl";
62
63enum {
64 OPT_s = 1,
65 OPT_l = 2
66};
67
68int cmp_main(int argc, char **argv)
69{
70 FILE *fp1, *fp2, *outfile = stdout;
71 const char *filename1, *filename2;
72 const char *fmt;
73 int c1, c2, char_pos, line_pos;
74 int opt_flags;
75 int exit_val = 0;
76
77 bb_default_error_retval = 2; /* 1 is returned if files are different. */
78
79 opt_flags = bb_getopt_ulflags(argc, argv, opt_chars);
80
81 if ((opt_flags == 3) || (((unsigned int)(--argc - optind)) > 1)) {
82 bb_show_usage();
83 }
84
85 fp1 = cmp_xfopen_input(filename1 = *(argv += optind));
86
87 filename2 = "-";
88 if (*++argv) {
89 filename2 = *argv;
90 }
91 fp2 = cmp_xfopen_input(filename2);
92
93 if (fp1 == fp2) { /* Paranioa check... stdin == stdin? */
94 /* Note that we don't bother reading stdin. Neither does gnu wc.
95 * But perhaps we should, so that other apps down the chain don't
96 * get the input. Consider 'echo hello | (cmp - - && cat -)'.
97 */
98 return 0;
99 }
100
101 fmt = fmt_differ;
102 if (opt_flags == OPT_l) {
103 fmt = fmt_l_opt;
104 }
105
106 char_pos = 0;
107 line_pos = 1;
108 do {
109 c1 = getc(fp1);
110 c2 = getc(fp2);
111 ++char_pos;
112 if (c1 != c2) { /* Remember -- a read error may have occurred. */
113 exit_val = 1; /* But assume the files are different for now. */
114 if (c2 == EOF) {
115 /* We know that fp1 isn't at EOF or in an error state. But to
116 * save space below, things are setup to expect an EOF in fp1
117 * if an EOF occurred. So, swap things around.
118 */
119 fp1 = fp2;
120 filename1 = filename2;
121 c1 = c2;
122 }
123 if (c1 == EOF) {
124 bb_xferror(fp1, filename1);
125 fmt = fmt_eof; /* Well, no error, so it must really be EOF. */
126 outfile = stderr;
127 /* There may have been output to stdout (option -l), so
128 * make sure we fflush before writing to stderr. */
129 bb_xfflush_stdout();
130 }
131 if (opt_flags != OPT_s) {
132 if (opt_flags == OPT_l) {
133 line_pos = c1; /* line_pos is unused in the -l case. */
134 }
135 bb_fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2);
136 if (opt_flags) { /* This must be -l since not -s. */
137 /* If we encountered and EOF, the while check will catch it. */
138 continue;
139 }
140 }
141 break;
142 }
143 if (c1 == '\n') {
144 ++line_pos;
145 }
146 } while (c1 != EOF);
147
148 bb_xferror(fp1, filename1);
149 bb_xferror(fp2, filename2);
150
151 bb_fflush_stdout_and_exit(exit_val);
152}