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 <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26
  27 #include "libbb.h"
  28 #include "unarchive.h"
  29
  30 #define GUNZIP_TO_STDOUT        1
  31 #define GUNZIP_FORCE    2
  32
  33 extern int uncompress_main(int argc, char **argv)
  34 {
  35         int status = EXIT_SUCCESS;
  36         unsigned long flags;
  37
  38         flags = bb_getopt_ulflags(argc, argv, "cf");
  39
  40         while (optind < argc) {
  41                 const char *compressed_file = argv[optind++];
  42                 const char *delete_path = NULL;
  43                 char *uncompressed_file = NULL;
  44                 int src_fd;
  45                 int dst_fd;
  46
  47                 if (strcmp(compressed_file, "-") == 0) {
  48                         src_fd = STDIN_FILENO;
  49                         flags |= GUNZIP_TO_STDOUT;
  50                 } else {
  51                         src_fd = bb_xopen(compressed_file, O_RDONLY);
  52                 }
  53
  54                 /* Check that the input is sane.  */
  55                 if (isatty(src_fd) && ((flags & GUNZIP_FORCE) == 0)) {
  56                         bb_error_msg_and_die
  57                                 ("compressed data not read from terminal.  Use -f to force it.");
  58                 }
  59
  60                 /* Set output filename and number */
  61                 if (flags & GUNZIP_TO_STDOUT) {
  62                         dst_fd = STDOUT_FILENO;
  63                 } else {
  64                         struct stat stat_buf;
  65                         char *extension;
  66
  67                         uncompressed_file = bb_xstrdup(compressed_file);
  68
  69                         extension = strrchr(uncompressed_file, '.');
  70                         if (!extension || (strcmp(extension, ".Z") != 0)) {
  71                                 bb_error_msg_and_die("Invalid extension");
  72                         }
  73                         *extension = '\0';
  74
  75                         /* Open output file */
  76                         dst_fd = bb_xopen(uncompressed_file, O_WRONLY | O_CREAT);
  77
  78                         /* Set permissions on the file */
  79                         stat(compressed_file, &stat_buf);
  80                         chmod(uncompressed_file, stat_buf.st_mode);
  81
  82                         /* If unzip succeeds remove the old file */
  83                         delete_path = compressed_file;
  84                 }
  85
  86                 /* do the decompression, and cleanup */
  87                 if ((bb_xread_char(src_fd) != 0x1f) || (bb_xread_char(src_fd) != 0x9d)) {
  88                         bb_error_msg_and_die("Invalid magic");
  89                 }
  90
  91                 status = uncompress(src_fd, dst_fd);
  92
  93                 if ((status != EXIT_SUCCESS) && (uncompressed_file)) {
  94                         /* Unzip failed, remove the uncomressed file instead of compressed file */
  95                         delete_path = uncompressed_file;
  96                 }
  97
  98                 if (dst_fd != STDOUT_FILENO) {
  99                         close(dst_fd);
 100                 }
 101                 if (src_fd != STDIN_FILENO) {
 102                         close(src_fd);
 103                 }
 104
 105                 /* delete_path will be NULL if in test mode or from stdin */
 106                 if (delete_path && (unlink(delete_path) == -1)) {
 107                         bb_error_msg_and_die("Couldn't remove %s", delete_path);
 108                 }
 109
 110                 free(uncompressed_file);
 111         }
 112
 113         return status;
 114 }