summaryrefslogtreecommitdiff
path: root/archival/gunzip.c
blob: ed4a3de36932c8c7b72294a1b1e7093a6cf148f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
/* vi: set sw=4 ts=4: */
/*
 * Gzip implementation for busybox
 *
 * Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
 *
 * Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
 * based on gzip sources
 *
 * Adjusted further by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 * to support files as well as stdin/stdout, and to generally behave itself wrt
 * command line handling.
 *
 * General cleanup to better adhere to the style guide and make use of standard
 * busybox functions by Glenn McGrath <bug1@optushome.com.au>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 *
 * gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
 * Copyright (C) 1992-1993 Jean-loup Gailly
 * The unzip code was written and put in the public domain by Mark Adler.
 * Portions of the lzw code are derived from the public domain 'compress'
 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
 * Ken Turkowski, Dave Mack and Peter Jannesen.
 *
 * See the license_msg below and the file COPYING for the software license.
 * See the file algorithm.doc for the compression algorithms and file formats.
 */

#if 0
static char *license_msg[] = {
	"   Copyright (C) 1992-1993 Jean-loup Gailly",
	"   This program is free software; you can redistribute it and/or modify",
	"   it under the terms of the GNU General Public License as published by",
	"   the Free Software Foundation; either version 2, or (at your option)",
	"   any later version.",
	"",
	"   This program is distributed in the hope that it will be useful,",
	"   but WITHOUT ANY WARRANTY; without even the implied warranty of",
	"   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the",
	"   GNU General Public License for more details.",
	"",
	"   You should have received a copy of the GNU General Public License",
	"   along with this program; if not, write to the Free Software",
	"   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.",
	0
};
#endif

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include "busybox.h"

extern int gunzip_main(int argc, char **argv)
{
	FILE *in_file, *out_file;
	struct stat stat_buf;

	char *if_name = NULL;
	char *of_name = NULL;
	char *delete_file_name = NULL;

	const int gunzip_to_stdout = 1;
	const int gunzip_force = 2;
	const int gunzip_test = 4;

	int flags = 0;
	int opt = 0;
	int delete_old_file = FALSE;

	/* if called as zcat */
	if (strcmp(applet_name, "zcat") == 0)
		flags |= gunzip_to_stdout;

	while ((opt = getopt(argc, argv, "ctfhdq")) != -1) {
		switch (opt) {
		case 'c':
			flags |= gunzip_to_stdout;
			break;
		case 'f':
			flags |= gunzip_force;
			break;
		case 't':
			flags |= gunzip_test;
			break;
		case 'd': /* Used to convert gzip to gunzip. */
			break;
		case 'q':
			error_msg("-q option not supported, ignored");
		case 'h':
		default:
			show_usage(); /* exit's inside usage */
		}
	}

	/* Set input filename and number */
	if (argv[optind] == NULL) {
		flags |= gunzip_to_stdout;
		in_file = stdin;
	} else {
		if_name = strdup(argv[optind]);
		/* Open input file */
		in_file = xfopen(if_name, "r");

		/* Get the time stamp on the input file. */
		if (stat(if_name, &stat_buf) < 0) {
			error_msg_and_die("Couldn't stat file %s", if_name);
		}
	}

	/* Check that the input is sane.  */
	if (isatty(fileno(in_file)) && (flags & gunzip_force) == 0)
		error_msg_and_die("compressed data not read from terminal.  Use -f to force it.");

	/* Set output filename and number */
	if (flags & gunzip_test) {
		out_file = xfopen("/dev/null", "w"); /* why does test use filenum 2 ? */
	} else if (flags & gunzip_to_stdout) {
		out_file = stdout;
	} else {
		char *extension;
		int length = strlen(if_name);

		delete_old_file = TRUE;
		extension = strrchr(if_name, '.');
		if (extension && strcmp(extension, ".gz") == 0) {
			length -= 3;
		} else if (extension && strcmp(extension, ".tgz") == 0) {
			length -= 4;
		} else {
			error_msg_and_die("Invalid extension");
		}
		of_name = (char *) xcalloc(sizeof(char), length + 1);
		strncpy(of_name, if_name, length);

		/* Open output file */
		out_file = xfopen(of_name, "w");

		/* Set permissions on the file */
		chmod(of_name, stat_buf.st_mode);
	}

	/* do the decompression, and cleanup */
	if (unzip(in_file, out_file) == 0) {
		/* Success, remove .gz file */
		delete_file_name = if_name;
	} else {
		/* remove failed attempt */
		delete_file_name = of_name;
	}

	fclose(out_file);
	fclose(in_file);

	if (delete_old_file == TRUE) {
		if (unlink(delete_file_name) < 0) {
			error_msg_and_die("Couldnt remove %s", delete_file_name);
		}
	}

	free(of_name);

	return(EXIT_SUCCESS);
}