1 /* Delete entries from a tar archive.
3 Copyright (C) 1988, 1992, 1994, 1996, 1997, 2000, 2001, 2003 Free
4 Software Foundation, Inc.
6 This program is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any later
11 This program is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
14 Public License for more details.
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
25 static union block *new_record;
26 static int new_blocks;
27 static bool acting_as_filter;
29 /* FIXME: This module should not directly handle the following
30 variables, instead, the interface should be cleaned up. */
31 extern union block *record_start;
32 extern union block *record_end;
33 extern union block *current_block;
34 extern union block *recent_long_name;
35 extern union block *recent_long_link;
36 extern off_t records_read;
37 extern off_t records_written;
39 /* The number of records skipped at the start of the archive, when
40 passing over members that are not deleted. */
41 static off_t records_skipped;
43 /* Move archive descriptor by COUNT records worth. If COUNT is
44 positive we move forward, else we move negative. If it's a tape,
45 MTIOCTOP had better work. If it's something else, we try to seek
46 on it. If we can't seek, we lose! */
48 move_archive (off_t count)
55 struct mtop operation;
58 ? (operation.mt_op = MTBSR,
59 operation.mt_count = -count,
60 operation.mt_count == -count)
61 : (operation.mt_op = MTFSR,
62 operation.mt_count = count,
63 operation.mt_count == count))
65 if (0 <= rmtioctl (archive, MTIOCTOP, (char *) &operation))
69 && 0 <= rmtioctl (archive, MTIOCTOP, (char *) &operation))
76 off_t position0 = rmtlseek (archive, (off_t) 0, SEEK_CUR);
77 off_t increment = record_size * (off_t) count;
78 off_t position = position0 + increment;
80 if (increment / count != record_size
81 || (position < position0) != (increment < 0)
82 || (position = position < 0 ? 0 : position,
83 rmtlseek (archive, position, SEEK_SET) != position))
84 seek_error_details (archive_name_array[0], position);
90 /* Write out the record which has been filled. If MOVE_BACK_FLAG,
91 backspace to where we started. */
93 write_record (int move_back_flag)
95 union block *save_record = record_start;
96 record_start = new_record;
100 archive = STDOUT_FILENO;
102 archive = STDIN_FILENO;
106 move_archive ((records_written + records_skipped) - records_read);
110 record_start = save_record;
114 /* Move the tape head back to where we were. */
116 if (! acting_as_filter)
117 move_archive (records_read - (records_written + records_skipped));
124 write_recent_blocks (union block *h, size_t blocks)
127 for (i = 0; i < blocks; i++)
129 new_record[new_blocks++] = h[i];
130 if (new_blocks == blocking_factor)
136 write_recent_bytes (char *data, size_t bytes)
138 size_t blocks = bytes / BLOCKSIZE;
139 size_t rest = bytes - blocks * BLOCKSIZE;
141 write_recent_blocks ((union block *)data, blocks);
142 memcpy (new_record[new_blocks].buffer, data + blocks * BLOCKSIZE, rest);
143 if (rest < BLOCKSIZE)
144 memset (new_record[new_blocks].buffer + rest, 0, BLOCKSIZE - rest);
146 if (new_blocks == blocking_factor)
151 delete_archive_members (void)
153 enum read_header logical_status = HEADER_STILL_UNREAD;
154 enum read_header previous_status = HEADER_STILL_UNREAD;
156 /* FIXME: Should clean the routine before cleaning these variables :-( */
158 off_t blocks_to_skip = 0;
159 off_t blocks_to_keep = 0;
160 int kept_blocks_in_record;
163 open_archive (ACCESS_UPDATE);
164 acting_as_filter = strcmp (archive_name_array[0], "-") == 0;
168 enum read_header status = read_header (true);
172 case HEADER_STILL_UNREAD:
176 if ((name = name_scan (current_stat_info.file_name)) == NULL)
189 case HEADER_SUCCESS_EXTENDED:
190 logical_status = status;
193 case HEADER_ZERO_BLOCK:
194 if (ignore_zeros_option)
196 set_next_block_after (current_header);
200 case HEADER_END_OF_FILE:
201 logical_status = HEADER_END_OF_FILE;
205 set_next_block_after (current_header);
206 switch (previous_status)
208 case HEADER_STILL_UNREAD:
209 WARN ((0, 0, _("This does not look like a tar archive")));
213 case HEADER_SUCCESS_EXTENDED:
214 case HEADER_ZERO_BLOCK:
215 ERROR ((0, 0, _("Skipping to next header")));
221 case HEADER_END_OF_FILE:
227 previous_status = status;
229 while (logical_status == HEADER_STILL_UNREAD);
231 records_skipped = records_read - 1;
232 new_record = xmalloc (record_size);
234 if (logical_status == HEADER_SUCCESS
235 || logical_status == HEADER_SUCCESS_EXTENDED)
237 write_archive_to_stdout = false;
239 /* Save away blocks before this one in this record. */
241 new_blocks = current_block - record_start;
243 memcpy (new_record, record_start, new_blocks * BLOCKSIZE);
245 if (logical_status == HEADER_SUCCESS)
247 /* FIXME: Pheew! This is crufty code! */
248 logical_status = HEADER_STILL_UNREAD;
252 /* FIXME: Solaris 2.4 Sun cc (the ANSI one, not the old K&R) says:
253 "delete.c", line 223: warning: loop not entered at top
254 Reported by Bruno Haible. */
257 enum read_header status;
259 /* Fill in a record. */
261 if (current_block == record_end)
263 status = read_header (false);
265 xheader_decode (¤t_stat_info);
267 if (status == HEADER_ZERO_BLOCK && ignore_zeros_option)
269 set_next_block_after (current_header);
272 if (status == HEADER_END_OF_FILE || status == HEADER_ZERO_BLOCK)
274 logical_status = HEADER_END_OF_FILE;
278 if (status == HEADER_FAILURE)
280 ERROR ((0, 0, _("Deleting non-header from archive")));
281 set_next_block_after (current_header);
285 /* Found another header. */
287 if ((name = name_scan (current_stat_info.file_name)) != NULL)
293 set_next_block_after (current_header);
294 blocks_to_skip = (current_stat_info.stat.st_size
295 + BLOCKSIZE - 1) / BLOCKSIZE;
297 while (record_end - current_block <= blocks_to_skip)
299 blocks_to_skip -= (record_end - current_block);
302 current_block += blocks_to_skip;
309 if (extended_header.size)
311 write_recent_bytes (extended_header.buffer,
312 extended_header.size);
316 write_recent_blocks (recent_long_name, recent_long_name_blocks);
317 write_recent_blocks (recent_long_link, recent_long_link_blocks);
319 new_record[new_blocks] = *current_header;
322 = (current_stat_info.stat.st_size + BLOCKSIZE - 1) / BLOCKSIZE;
323 set_next_block_after (current_header);
324 if (new_blocks == blocking_factor)
329 kept_blocks_in_record = record_end - current_block;
330 if (kept_blocks_in_record > blocks_to_keep)
331 kept_blocks_in_record = blocks_to_keep;
333 while (blocks_to_keep)
337 if (current_block == record_end)
340 current_block = record_start;
341 kept_blocks_in_record = blocking_factor;
342 if (kept_blocks_in_record > blocks_to_keep)
343 kept_blocks_in_record = blocks_to_keep;
345 count = kept_blocks_in_record;
346 if (blocking_factor - new_blocks < count)
347 count = blocking_factor - new_blocks;
352 memcpy (new_record + new_blocks, current_block, count * BLOCKSIZE);
354 current_block += count;
355 blocks_to_keep -= count;
356 kept_blocks_in_record -= count;
358 if (new_blocks == blocking_factor)
364 if (logical_status == HEADER_END_OF_FILE)
366 /* Write the end of tape. FIXME: we can't use write_eot here,
367 as it gets confused when the input is at end of file. */
369 int total_zero_blocks = 0;
373 int zero_blocks = blocking_factor - new_blocks;
374 memset (new_record + new_blocks, 0, BLOCKSIZE * zero_blocks);
375 total_zero_blocks += zero_blocks;
376 write_record (total_zero_blocks < 2);
378 while (total_zero_blocks < 2);
383 if (! acting_as_filter && ! _isrmt (archive))
385 if (sys_truncate (archive))
386 truncate_warn (archive_name_array[0]);