busybox/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
*
* 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
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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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extern int gunzip_main(int argc, char **argv)
{
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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;
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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");
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break;
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");
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/* 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);
}
}
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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;
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");
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/* 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);
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}