1 /* Update a tar archive.
2 Copyright 1988, 92, 94, 96, 97, 99, 2000 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 2, or (at your option) any later
9 This program is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
12 Public License for more details.
14 You should have received a copy of the GNU General Public License along
15 with this program; if not, write to the Free Software Foundation, Inc.,
16 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 /* Implement the 'r', 'u' and 'A' options for tar. 'A' means that the
19 file names are tar files, and they should simply be appended to the end
20 of the archive. No attempt is made to record the reads from the args; if
21 they're on raw tape or something like that, it'll probably lose... */
27 /* FIXME: This module should not directly handle the following variable,
28 instead, this should be done in buffer.c only. */
29 extern union block *current_block;
31 /* We've hit the end of the old stuff, and its time to start writing new
32 stuff to the tape. This involves seeking back one record and
33 re-writing the current record (which has been changed). */
34 int time_to_start_writing;
36 /* Pointer to where we started to write in the first record we write out.
37 This is used if we can't backspace the output and have to null out the
38 first part of the record. */
41 /* Catenate file PATH to the archive without creating a header for it.
42 It had better be a tar file or the archive is screwed. */
44 append_file (char *path)
46 int handle = open (path, O_RDONLY | O_BINARY);
47 struct stat stat_data;
55 if (fstat (handle, &stat_data) != 0)
59 off_t bytes_left = stat_data.st_size;
61 while (bytes_left > 0)
63 union block *start = find_next_block ();
64 size_t buffer_size = available_space_after (start);
66 char buf[UINTMAX_STRSIZE_BOUND];
68 if (bytes_left < buffer_size)
70 buffer_size = bytes_left;
71 status = buffer_size % BLOCKSIZE;
73 memset (start->buffer + bytes_left, 0, BLOCKSIZE - status);
76 status = safe_read (handle, start->buffer, buffer_size);
78 read_fatal_details (path, stat_data.st_size - bytes_left,
81 FATAL_ERROR ((0, 0, _("%s: File shrank by %s bytes"),
82 quotearg_colon (path),
83 STRINGIFY_BIGINT (bytes_left, buf)));
87 set_next_block_after (start + (status - 1) / BLOCKSIZE);
91 if (close (handle) != 0)
95 /* Implement the 'r' (add files to end of archive), and 'u' (add files
96 to end of archive if they aren't there, or are more up to date than
97 the version in the archive) commands. */
101 enum read_header previous_status = HEADER_STILL_UNREAD;
105 open_archive (ACCESS_UPDATE);
109 enum read_header status = read_header ();
113 case HEADER_STILL_UNREAD:
120 if (subcommand_option == UPDATE_SUBCOMMAND
121 && (name = name_scan (current_file_name), name))
124 enum archive_format unused;
126 decode_header (current_header, ¤t_stat, &unused, 0);
127 chdir_do (name->change_dir);
128 if (deref_stat (dereference_option, current_file_name, &s) == 0
129 && s.st_mtime <= current_stat.st_mtime)
130 add_avoided_name (current_file_name);
136 case HEADER_ZERO_BLOCK:
137 current_block = current_header;
141 case HEADER_END_OF_FILE:
146 set_next_block_after (current_header);
147 switch (previous_status)
149 case HEADER_STILL_UNREAD:
150 WARN ((0, 0, _("This does not look like a tar archive")));
154 case HEADER_ZERO_BLOCK:
155 ERROR ((0, 0, _("Skipping to next header")));
161 case HEADER_END_OF_FILE:
167 previous_status = status;
171 time_to_start_writing = 1;
172 output_start = current_block->buffer;
177 while (path = name_from_list (), path)
179 if (excluded_name (path))
181 if (interactive_option && !confirm ("add", path))
183 if (subcommand_option == CAT_SUBCOMMAND)
186 dump_file (path, 1, (dev_t) 0);