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