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 int uncompress_main(int argc, char **argv)
  32 {
  33         const char gunzip_to_stdout = 1;
  34         const char gunzip_force = 2;
  35         char status = EXIT_SUCCESS;
  36         char flags = 0;
  37         int opt;
  38
  39         while ((opt = getopt(argc, argv, "cfh")) != -1) {
  40                 switch (opt) {
  41                 case 'c':
  42                         flags |= gunzip_to_stdout;
  43                         break;
  44                 case 'f':
  45                         flags |= gunzip_force;
  46                         break;
  47                 default:
  48                         show_usage();   /* exit's inside usage */
  49                 }
  50         }
  51
  52         do {
  53                 struct stat stat_buf;
  54                 const char *old_path = argv[optind];
  55                 const char *delete_path = NULL;
  56                 char *new_path = NULL;
  57                 int src_fd;
  58                 int dst_fd;
  59
  60                 optind++;
  61
  62                 if (old_path == NULL || strcmp(old_path, "-") == 0) {
  63                         src_fd = fileno(stdin);
  64                         flags |= gunzip_to_stdout;
  65                 } else {
  66                         src_fd = xopen(old_path, O_RDONLY);
  67
  68                         /* Get the time stamp on the input file. */
  69                         if (stat(old_path, &stat_buf) < 0) {
  70                                 error_msg_and_die("Couldn't stat file %s", old_path);
  71                         }
  72                 }
  73
  74                 /* Check that the input is sane.  */
  75                 if (isatty(src_fd) && ((flags & gunzip_force) == 0)) {
  76                         error_msg_and_die
  77                                 ("compressed data not read from terminal.  Use -f to force it.");
  78                 }
  79
  80                 /* Set output filename and number */
  81                 if (flags & gunzip_to_stdout) {
  82                         dst_fd = fileno(stdout);
  83                 } else {
  84                         char *extension;
  85
  86                         new_path = xstrdup(old_path);
  87
  88                         extension = strrchr(new_path, '.');
  89                         if (!extension || (strcmp(extension, ".Z") != 0)) {
  90                                 error_msg_and_die("Invalid extension");
  91                         }
  92                         *extension = '\0';
  93
  94                         /* Open output file */
  95                         dst_fd = xopen(new_path, O_WRONLY | O_CREAT);
  96
  97                         /* Set permissions on the file */
  98                         chmod(new_path, stat_buf.st_mode);
  99
 100                         /* If unzip succeeds remove the old file */
 101                         delete_path = old_path;
 102                 }
 103
 104                 /* do the decompression, and cleanup */
 105                 if ((xread_char(src_fd) == 0x1f) && (xread_char(src_fd) == 0x9d)) {
 106                         status = uncompress(src_fd, dst_fd);
 107                 } else {
 108                         error_msg_and_die("Invalid magic");
 109                 }
 110
 111                 if ((status != EXIT_SUCCESS) && (new_path)) {
 112                         /* Unzip failed, remove new path instead of old path */
 113                         delete_path = new_path;
 114                 }
 115
 116                 if (dst_fd != fileno(stdout)) {
 117                         close(dst_fd);
 118                 }
 119                 if (src_fd != fileno(stdin)) {
 120                         close(src_fd);
 121                 }
 122
 123                 /* delete_path will be NULL if in test mode or from stdin */
 124                 if (delete_path && (unlink(delete_path) == -1)) {
 125                         error_msg_and_die("Couldn't remove %s", delete_path);
 126                 }
 127
 128                 free(new_path);
 129
 130         } while (optind < argc);
 131
 132         return status;
 133 }