busybox/archival/gunzip.c

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/* 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
*
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* Adjusted further by Erik Andersen <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
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* 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
};
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#endif
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#include <stdlib.h>
#include <string.h>
#include <unistd.h>
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#include <getopt.h>
#include "busybox.h"
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const char gunzip_to_stdout = 1;
const char gunzip_force = 2;
const char gunzip_test = 4;
extern int gunzip_main(int argc, char **argv)
{
char status = EXIT_SUCCESS;
char flags = 0;
int opt;
/* if called as zcat */
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if (strcmp(applet_name, "zcat") == 0) {
flags |= gunzip_to_stdout;
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}
while ((opt = getopt(argc, argv, "ctfhd")) != -1) {
switch (opt) {
case 'c':
flags |= gunzip_to_stdout;
break;
case 'f':
flags |= gunzip_force;
break;
case 't':
flags |= gunzip_test;
break;
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case 'd': /* Used to convert gzip to gunzip. */
break;
default:
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show_usage(); /* exit's inside usage */
}
}
do {
FILE *in_file, *out_file;
struct stat stat_buf;
const char *old_path = argv[optind];
const char *delete_path = NULL;
char *new_path = NULL;
optind++;
if (old_path == NULL || strcmp(old_path, "-") == 0) {
in_file = stdin;
flags |= gunzip_to_stdout;
} else {
in_file = wfopen(old_path, "r");
if (in_file == NULL) {
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status = EXIT_FAILURE;
break;
}
/* Get the time stamp on the input file. */
if (stat(old_path, &stat_buf) < 0) {
error_msg_and_die("Couldn't stat file %s", old_path);
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}
}
/* 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;
new_path = xstrdup(old_path);
extension = strrchr(new_path, '.');
if (extension && (strcmp(extension, ".gz") == 0)) {
*extension = '\0';
} else if (extension && (strcmp(extension, ".tgz") == 0)) {
extension[2] = 'a';
extension[3] = 'r';
} else {
error_msg_and_die("Invalid extension");
}
/* Open output file */
out_file = xfopen(new_path, "w");
/* Set permissions on the file */
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chmod(new_path, stat_buf.st_mode);
/* If unzip succeeds remove the old file */
delete_path = old_path;
}
/* do the decompression, and cleanup */
if ((unzip(in_file, out_file) != 0) && (new_path)) {
/* Unzip failed, remove new path instead of old path */
delete_path = new_path;
}
if (out_file != stdout) {
fclose(out_file);
}
if (in_file != stdin) {
fclose(in_file);
}
/* delete_path will be NULL if in test mode or from stdin */
if (delete_path && (unlink(delete_path) == -1)) {
error_msg_and_die("Couldn't remove %s", delete_path);
}
free(new_path);
} while (optind < argc);
return status;
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}