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.
33 #include <sys/types.h>
38 #include "unarchive.h"
40 #define GUNZIP_OPT_STDOUT 1
41 #define GUNZIP_OPT_FORCE 2
42 #define GUNZIP_OPT_TEST 4
43 #define GUNZIP_OPT_DECOMPRESS 8
45 int gunzip_main(int argc, char **argv)
47 char status = EXIT_SUCCESS;
50 opt = bb_getopt_ulflags(argc, argv, "cftd");
51 /* if called as zcat */
52 if (strcmp(bb_applet_name, "zcat") == 0) {
53 opt |= GUNZIP_OPT_STDOUT;
58 const char *old_path = argv[optind];
59 const char *delete_path = NULL;
60 char *new_path = NULL;
66 if (old_path == NULL || strcmp(old_path, "-") == 0) {
67 src_fd = STDIN_FILENO;
68 opt |= GUNZIP_OPT_STDOUT;
70 src_fd = bb_xopen(old_path, O_RDONLY);
72 /* Get the time stamp on the input file. */
73 xstat(old_path, &stat_buf);
76 /* Check that the input is sane. */
77 if (isatty(src_fd) && ((opt & GUNZIP_OPT_FORCE) == 0)) {
79 ("compressed data not read from terminal. Use -f to force it.");
82 /* Set output filename and number */
83 if (opt & GUNZIP_OPT_TEST) {
84 dst_fd = bb_xopen(bb_dev_null, O_WRONLY); /* why does test use filenum 2 ? */
85 } else if (opt & GUNZIP_OPT_STDOUT) {
86 dst_fd = STDOUT_FILENO;
90 new_path = bb_xstrdup(old_path);
92 extension = strrchr(new_path, '.');
93 #ifdef CONFIG_FEATURE_GUNZIP_UNCOMPRESS
94 if (extension && (strcmp(extension, ".Z") == 0)) {
98 if (extension && (strcmp(extension, ".gz") == 0)) {
100 } else if (extension && (strcmp(extension, ".tgz") == 0)) {
104 bb_error_msg_and_die("Invalid extension");
107 /* Open output file (with correct permissions) */
108 dst_fd = bb_xopen3(new_path, O_WRONLY | O_CREAT, stat_buf.st_mode);
110 /* If unzip succeeds remove the old file */
111 delete_path = old_path;
114 /* do the decompression, and cleanup */
115 if (bb_xread_char(src_fd) == 0x1f) {
116 unsigned char magic2;
118 magic2 = bb_xread_char(src_fd);
119 #ifdef CONFIG_FEATURE_GUNZIP_UNCOMPRESS
120 if (magic2 == 0x9d) {
121 status = uncompress(src_fd, dst_fd);
124 if (magic2 == 0x8b) {
125 check_header_gzip(src_fd);
126 status = inflate_gunzip(src_fd, dst_fd);
128 bb_error_msg_and_die("Error inflating");
131 bb_error_msg_and_die("Invalid magic");
134 bb_error_msg_and_die("Invalid magic");
137 if ((status != EXIT_SUCCESS) && (new_path)) {
138 /* Unzip failed, remove new path instead of old path */
139 delete_path = new_path;
142 if (dst_fd != STDOUT_FILENO) {
145 if (src_fd != STDIN_FILENO) {
149 /* delete_path will be NULL if in test mode or from stdin */
150 if (delete_path && (unlink(delete_path) == -1)) {
151 bb_error_msg_and_die("Couldn't remove %s", delete_path);
156 } while (optind < argc);