aboutsummaryrefslogtreecommitdiff
path: root/archival/gunzip.c
blob: e24401c71ba654038249cee2932ee025d01aea8a (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
/* 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@codepoet.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@iinet.net.au>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 *
 * 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.
 */

#include "busybox.h"
#include "unarchive.h"

#define GUNZIP_OPT_STDOUT	1
#define GUNZIP_OPT_FORCE	2
#define GUNZIP_OPT_TEST		4
#define GUNZIP_OPT_DECOMPRESS	8
#define GUNZIP_OPT_VERBOSE	0x10

int gunzip_main(int argc, char **argv)
{
	USE_DESKTOP(long long) int status;
	int exitcode = 0;
	unsigned opt;

	opt = getopt32(argc, argv, "cftdv");
	/* if called as zcat */
	if (strcmp(applet_name, "zcat") == 0) {
		opt |= GUNZIP_OPT_STDOUT;
	}

	do {
		struct stat stat_buf;
		char *old_path = argv[optind];
		char *delete_path = NULL;
		char *new_path = NULL;
		int src_fd;
		int dst_fd;

		optind++;

		if (old_path == NULL || strcmp(old_path, "-") == 0) {
			src_fd = STDIN_FILENO;
			opt |= GUNZIP_OPT_STDOUT;
			USE_DESKTOP(opt &= ~GUNZIP_OPT_VERBOSE;)
			optind = argc; /* we don't handle "gunzip - a.gz b.gz" */
		} else {
			src_fd = xopen(old_path, O_RDONLY);
			/* Get the time stamp on the input file. */
			fstat(src_fd, &stat_buf);
		}

		/* Check that the input is sane.  */
		if (isatty(src_fd) && !(opt & GUNZIP_OPT_FORCE)) {
			bb_error_msg_and_die
				("compressed data not read from terminal, use -f to force it");
		}

		/* Set output filename and number */
		if (opt & GUNZIP_OPT_TEST) {
			dst_fd = xopen(bb_dev_null, O_WRONLY);	/* why does test use filenum 2 ? */
		} else if (opt & GUNZIP_OPT_STDOUT) {
			dst_fd = STDOUT_FILENO;
		} else {
			char *extension;

			new_path = xstrdup(old_path);

			extension = strrchr(new_path, '.');
#ifdef CONFIG_FEATURE_GUNZIP_UNCOMPRESS
			if (extension && (strcmp(extension, ".Z") == 0)) {
				*extension = '\0';
			} else
#endif
			if (extension && (strcmp(extension, ".gz") == 0)) {
				*extension = '\0';
			} else if (extension && (strcmp(extension, ".tgz") == 0)) {
				extension[2] = 'a';
				extension[3] = 'r';
			} else {
				// FIXME: should we die or just skip to next?
				bb_error_msg_and_die("invalid extension");
			}

			/* Open output file (with correct permissions) */
			dst_fd = xopen3(new_path, O_WRONLY | O_CREAT | O_TRUNC,
					stat_buf.st_mode);

			/* If unzip succeeds remove the old file */
			delete_path = old_path;
		}

		status = -1;
		/* do the decompression, and cleanup */
		if (xread_char(src_fd) == 0x1f) {
			unsigned char magic2;

			magic2 = xread_char(src_fd);
			if (ENABLE_FEATURE_GUNZIP_UNCOMPRESS && magic2 == 0x9d) {
				status = uncompress(src_fd, dst_fd);
			} else if (magic2 == 0x8b) {
				check_header_gzip(src_fd); // FIXME: xfunc? _or_die?
				status = inflate_gunzip(src_fd, dst_fd);
			} else {
				bb_error_msg("invalid magic");
				exitcode = 1;
			}
			if (status < 0) {
				bb_error_msg("error inflating");
				exitcode = 1;
			}
			else if (ENABLE_DESKTOP && (opt & GUNZIP_OPT_VERBOSE)) {
				fprintf(stderr, "%s: %u%% - replaced with %s\n",
					old_path, (unsigned)(stat_buf.st_size*100 / (status+1)), new_path);
			}
		} else {
			bb_error_msg("invalid magic");
			exitcode = 1;
		}
		if (status < 0 && new_path) {
			/* Unzip failed, remove new path instead of old path */
			delete_path = new_path;
		}

		if (dst_fd != STDOUT_FILENO) {
			close(dst_fd);
		}
		if (src_fd != STDIN_FILENO) {
			close(src_fd);
		}

		/* delete_path will be NULL if in test mode or from stdin */
		if (delete_path && (unlink(delete_path) == -1)) {
			bb_error_msg("cannot remove %s", delete_path);
			exitcode = 1;
		}

		free(new_path);

	} while (optind < argc);

	return exitcode;
}