1 /* vi: set sw=4 ts=4: */
3 * Gzip implementation for busybox
5 * Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
7 * Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
8 * based on gzip sources
10 * Adjusted further by Erik Andersen <andersen@codepoet.org> to support files as
11 * well as stdin/stdout, and to generally behave itself wrt command line
14 * General cleanup to better adhere to the style guide and make use of standard
15 * busybox functions by Glenn McGrath <bug1@iinet.net.au>
17 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
19 * gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
20 * Copyright (C) 1992-1993 Jean-loup Gailly
21 * The unzip code was written and put in the public domain by Mark Adler.
22 * Portions of the lzw code are derived from the public domain 'compress'
23 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
24 * Ken Turkowski, Dave Mack and Peter Jannesen.
26 * See the license_msg below and the file COPYING for the software license.
27 * See the file algorithm.doc for the compression algorithms and file formats.
31 #include "unarchive.h"
33 #define GUNZIP_OPT_STDOUT 1
34 #define GUNZIP_OPT_FORCE 2
35 #define GUNZIP_OPT_TEST 4
36 #define GUNZIP_OPT_DECOMPRESS 8
38 int gunzip_main(int argc, char **argv)
40 char status = EXIT_SUCCESS;
43 opt = bb_getopt_ulflags(argc, argv, "cftd");
44 /* if called as zcat */
45 if (strcmp(bb_applet_name, "zcat") == 0) {
46 opt |= GUNZIP_OPT_STDOUT;
51 char *old_path = argv[optind];
52 char *delete_path = NULL;
53 char *new_path = NULL;
59 if (old_path == NULL || strcmp(old_path, "-") == 0) {
60 src_fd = STDIN_FILENO;
61 opt |= GUNZIP_OPT_STDOUT;
63 src_fd = xopen(old_path, O_RDONLY);
65 /* Get the time stamp on the input file. */
66 xstat(old_path, &stat_buf);
69 /* Check that the input is sane. */
70 if (isatty(src_fd) && ((opt & GUNZIP_OPT_FORCE) == 0)) {
72 ("compressed data not read from terminal. Use -f to force it.");
75 /* Set output filename and number */
76 if (opt & GUNZIP_OPT_TEST) {
77 dst_fd = xopen(bb_dev_null, O_WRONLY); /* why does test use filenum 2 ? */
78 } else if (opt & GUNZIP_OPT_STDOUT) {
79 dst_fd = STDOUT_FILENO;
83 new_path = xstrdup(old_path);
85 extension = strrchr(new_path, '.');
86 #ifdef CONFIG_FEATURE_GUNZIP_UNCOMPRESS
87 if (extension && (strcmp(extension, ".Z") == 0)) {
91 if (extension && (strcmp(extension, ".gz") == 0)) {
93 } else if (extension && (strcmp(extension, ".tgz") == 0)) {
97 bb_error_msg_and_die("Invalid extension");
100 /* Open output file (with correct permissions) */
101 dst_fd = xopen3(new_path, O_WRONLY | O_CREAT | O_TRUNC,
104 /* If unzip succeeds remove the old file */
105 delete_path = old_path;
108 /* do the decompression, and cleanup */
109 if (xread_char(src_fd) == 0x1f) {
110 unsigned char magic2;
112 magic2 = xread_char(src_fd);
113 #ifdef CONFIG_FEATURE_GUNZIP_UNCOMPRESS
114 if (magic2 == 0x9d) {
115 status = uncompress(src_fd, dst_fd);
118 if (magic2 == 0x8b) {
119 check_header_gzip(src_fd);
120 status = inflate_gunzip(src_fd, dst_fd);
122 bb_error_msg_and_die("error inflating");
125 bb_error_msg_and_die("invalid magic");
128 bb_error_msg_and_die("invalid magic");
131 if ((status != EXIT_SUCCESS) && (new_path)) {
132 /* Unzip failed, remove new path instead of old path */
133 delete_path = new_path;
136 if (dst_fd != STDOUT_FILENO) {
139 if (src_fd != STDIN_FILENO) {
143 /* delete_path will be NULL if in test mode or from stdin */
144 if (delete_path && (unlink(delete_path) == -1)) {
145 bb_error_msg_and_die("cannot remove %s", delete_path);
150 } while (optind < argc);