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 <stdlib.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <sys/types.h>
  12 #include <sys/stat.h>
  13 #include <fcntl.h>
  14
  15 #include "busybox.h"
  16 #include "unarchive.h"
  17
  18 #define GUNZIP_TO_STDOUT        1
  19 #define GUNZIP_FORCE    2
  20
  21 int uncompress_main(int argc, char **argv)
  22 {
  23         int status = EXIT_SUCCESS;
  24         unsigned long flags;
  25
  26         flags = bb_getopt_ulflags(argc, argv, "cf");
  27
  28         while (optind < argc) {
  29                 const char *compressed_file = argv[optind++];
  30                 const char *delete_path = NULL;
  31                 char *uncompressed_file = NULL;
  32                 int src_fd;
  33                 int dst_fd;
  34
  35                 if (strcmp(compressed_file, "-") == 0) {
  36                         src_fd = STDIN_FILENO;
  37                         flags |= GUNZIP_TO_STDOUT;
  38                 } else {
  39                         src_fd = bb_xopen(compressed_file, O_RDONLY);
  40                 }
  41
  42                 /* Check that the input is sane.  */
  43                 if (isatty(src_fd) && ((flags & GUNZIP_FORCE) == 0)) {
  44                         bb_error_msg_and_die
  45                                 ("compressed data not read from terminal.  Use -f to force it.");
  46                 }
  47
  48                 /* Set output filename and number */
  49                 if (flags & GUNZIP_TO_STDOUT) {
  50                         dst_fd = STDOUT_FILENO;
  51                 } else {
  52                         struct stat stat_buf;
  53                         char *extension;
  54
  55                         uncompressed_file = bb_xstrdup(compressed_file);
  56
  57                         extension = strrchr(uncompressed_file, '.');
  58                         if (!extension || (strcmp(extension, ".Z") != 0)) {
  59                                 bb_error_msg_and_die("Invalid extension");
  60                         }
  61                         *extension = '\0';
  62
  63                         /* Open output file */
  64                         dst_fd = bb_xopen(uncompressed_file, O_WRONLY | O_CREAT);
  65
  66                         /* Set permissions on the file */
  67                         stat(compressed_file, &stat_buf);
  68                         chmod(uncompressed_file, stat_buf.st_mode);
  69
  70                         /* If unzip succeeds remove the old file */
  71                         delete_path = compressed_file;
  72                 }
  73
  74                 /* do the decompression, and cleanup */
  75                 if ((bb_xread_char(src_fd) != 0x1f) || (bb_xread_char(src_fd) != 0x9d)) {
  76                         bb_error_msg_and_die("Invalid magic");
  77                 }
  78
  79                 status = uncompress(src_fd, dst_fd);
  80
  81                 if ((status != EXIT_SUCCESS) && (uncompressed_file)) {
  82                         /* Unzip failed, remove the uncomressed file instead of compressed file */
  83                         delete_path = uncompressed_file;
  84                 }
  85
  86                 if (dst_fd != STDOUT_FILENO) {
  87                         close(dst_fd);
  88                 }
  89                 if (src_fd != STDIN_FILENO) {
  90                         close(src_fd);
  91                 }
  92
  93                 /* delete_path will be NULL if in test mode or from stdin */
  94                 if (delete_path && (unlink(delete_path) == -1)) {
  95                         bb_error_msg_and_die("Couldn't remove %s", delete_path);
  96                 }
  97
  98                 free(uncompressed_file);
  99         }
 100
 101         return status;
 102 }