busybox/archival/uncompress.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *      Uncompress applet for busybox (c) 2002 Glenn McGrath
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <getopt.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27
  28 #include "libbb.h"
  29 #include "unarchive.h"
  30
  31 #define GUNZIP_TO_STDOUT        1
  32 #define GUNZIP_FORCE    2
  33
  34 extern int uncompress_main(int argc, char **argv)
  35 {
  36         int status = EXIT_SUCCESS;
  37         unsigned long flags;
  38
  39         flags = bb_getopt_ulflags(argc, argv, "cf");
  40
  41         while (optind < argc) {
  42                 const char *compressed_file = argv[optind++];
  43                 const char *delete_path = NULL;
  44                 char *uncompressed_file = NULL;
  45                 int src_fd;
  46                 int dst_fd;
  47
  48                 if (strcmp(compressed_file, "-") == 0) {
  49                         src_fd = STDIN_FILENO;
  50                         flags |= GUNZIP_TO_STDOUT;
  51                 } else {
  52                         src_fd = bb_xopen(compressed_file, O_RDONLY);
  53                 }
  54
  55                 /* Check that the input is sane.  */
  56                 if (isatty(src_fd) && ((flags & GUNZIP_FORCE) == 0)) {
  57                         bb_error_msg_and_die
  58                                 ("compressed data not read from terminal.  Use -f to force it.");
  59                 }
  60
  61                 /* Set output filename and number */
  62                 if (flags & GUNZIP_TO_STDOUT) {
  63                         dst_fd = STDOUT_FILENO;
  64                 } else {
  65                         struct stat stat_buf;
  66                         char *extension;
  67
  68                         uncompressed_file = bb_xstrdup(compressed_file);
  69
  70                         extension = strrchr(uncompressed_file, '.');
  71                         if (!extension || (strcmp(extension, ".Z") != 0)) {
  72                                 bb_error_msg_and_die("Invalid extension");
  73                         }
  74                         *extension = '\0';
  75
  76                         /* Open output file */
  77                         dst_fd = bb_xopen(uncompressed_file, O_WRONLY | O_CREAT);
  78
  79                         /* Set permissions on the file */
  80                         stat(compressed_file, &stat_buf);
  81                         chmod(uncompressed_file, stat_buf.st_mode);
  82
  83                         /* If unzip succeeds remove the old file */
  84                         delete_path = compressed_file;
  85                 }
  86
  87                 /* do the decompression, and cleanup */
  88                 if ((bb_xread_char(src_fd) != 0x1f) || (bb_xread_char(src_fd) != 0x9d)) {
  89                         bb_error_msg_and_die("Invalid magic");
  90                 }
  91
  92                 status = uncompress(src_fd, dst_fd);
  93
  94                 if ((status != EXIT_SUCCESS) && (uncompressed_file)) {
  95                         /* Unzip failed, remove the uncomressed file instead of compressed file */
  96                         delete_path = uncompressed_file;
  97                 }
  98
  99                 if (dst_fd != STDOUT_FILENO) {
 100                         close(dst_fd);
 101                 }
 102                 if (src_fd != STDIN_FILENO) {
 103                         close(src_fd);
 104                 }
 105
 106                 /* delete_path will be NULL if in test mode or from stdin */
 107                 if (delete_path && (unlink(delete_path) == -1)) {
 108                         bb_error_msg_and_die("Couldn't remove %s", delete_path);
 109                 }
 110
 111                 free(uncompressed_file);
 112         }
 113
 114         return status;
 115 }