archival/uncompress.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  *      Uncompress applet for busybox (c) 2002 Glenn McGrath
   4  *
   5  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   6  */
   7
   8 #include "busybox.h"
   9 #include "unarchive.h"
  10
  11 #define GUNZIP_TO_STDOUT        1
  12 #define GUNZIP_FORCE    2
  13
  14 int uncompress_main(int argc, char **argv);
  15 int uncompress_main(int argc, char **argv)
  16 {
  17         int status = EXIT_SUCCESS;
  18         unsigned long flags;
  19
  20         flags = getopt32(argc, argv, "cf");
  21
  22         while (optind < argc) {
  23                 char *compressed_file = argv[optind++];
  24                 char *delete_path = NULL;
  25                 char *uncompressed_file = NULL;
  26                 int src_fd;
  27                 int dst_fd;
  28
  29                 if (LONE_DASH(compressed_file)) {
  30                         src_fd = STDIN_FILENO;
  31                         flags |= GUNZIP_TO_STDOUT;
  32                 } else {
  33                         src_fd = xopen(compressed_file, O_RDONLY);
  34                 }
  35
  36                 /* Check that the input is sane.  */
  37                 if (isatty(src_fd) && ((flags & GUNZIP_FORCE) == 0)) {
  38                         bb_error_msg_and_die
  39                                 ("compressed data not read from terminal.  Use -f to force it.");
  40                 }
  41
  42                 /* Set output filename and number */
  43                 if (flags & GUNZIP_TO_STDOUT) {
  44                         dst_fd = STDOUT_FILENO;
  45                 } else {
  46                         struct stat stat_buf;
  47                         char *extension;
  48
  49                         uncompressed_file = xstrdup(compressed_file);
  50
  51                         extension = strrchr(uncompressed_file, '.');
  52                         if (!extension || (strcmp(extension, ".Z") != 0)) {
  53                                 bb_error_msg_and_die("invalid extension");
  54                         }
  55                         *extension = '\0';
  56
  57                         /* Open output file */
  58                         xstat(compressed_file, &stat_buf);
  59                         dst_fd = xopen3(uncompressed_file,
  60                                         O_WRONLY | O_CREAT | O_TRUNC,
  61                                         stat_buf.st_mode);
  62
  63                         /* If unzip succeeds remove the old file */
  64                         delete_path = compressed_file;
  65                 }
  66
  67                 /* do the decompression, and cleanup */
  68                 if ((xread_char(src_fd) != 0x1f) || (xread_char(src_fd) != 0x9d)) {
  69                         bb_error_msg_and_die("invalid magic");
  70                 }
  71
  72                 status = uncompress(src_fd, dst_fd);
  73
  74                 if ((status != EXIT_SUCCESS) && (uncompressed_file)) {
  75                         /* Unzip failed, remove the uncomressed file instead of compressed file */
  76                         delete_path = uncompressed_file;
  77                 }
  78
  79                 if (dst_fd != STDOUT_FILENO) {
  80                         close(dst_fd);
  81                 }
  82                 if (src_fd != STDIN_FILENO) {
  83                         close(src_fd);
  84                 }
  85
  86                 /* delete_path will be NULL if in test mode or from stdin */
  87                 if (delete_path && (unlink(delete_path) == -1)) {
  88                         bb_error_msg_and_die("cannot remove %s", delete_path);
  89                 }
  90
  91                 free(uncompressed_file);
  92         }
  93
  94         return status;
  95 }