1 /* Delete entries from a tar archive.
3 Copyright (C) 1988, 1992, 1994, 1996, 1997, 2000, 2001 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 size_t recent_long_name_blocks
;
37 extern size_t recent_long_link_blocks
;
38 extern off_t records_read
;
39 extern off_t records_written
;
41 /* The number of records skipped at the start of the archive, when
42 passing over members that are not deleted. */
43 static off_t records_skipped
;
45 /* Move archive descriptor by COUNT records worth. If COUNT is
46 positive we move forward, else we move negative. If it's a tape,
47 MTIOCTOP had better work. If it's something else, we try to seek
48 on it. If we can't seek, we lose! */
50 move_archive (off_t count
)
57 struct mtop operation
;
60 ? (operation
.mt_op
= MTBSR
,
61 operation
.mt_count
= -count
,
62 operation
.mt_count
== -count
)
63 : (operation
.mt_op
= MTFSR
,
64 operation
.mt_count
= count
,
65 operation
.mt_count
== count
))
67 if (0 <= rmtioctl (archive
, MTIOCTOP
, (char *) &operation
))
71 && 0 <= rmtioctl (archive
, MTIOCTOP
, (char *) &operation
))
78 off_t position0
= rmtlseek (archive
, (off_t
) 0, SEEK_CUR
);
79 off_t increment
= record_size
* (off_t
) count
;
80 off_t position
= position0
+ increment
;
82 if (increment
/ count
!= record_size
83 || (position
< position0
) != (increment
< 0)
84 || (position
= position
< 0 ? 0 : position
,
85 rmtlseek (archive
, position
, SEEK_SET
) != position
))
86 seek_error_details (archive_name_array
[0], position
);
92 /* Write out the record which has been filled. If MOVE_BACK_FLAG,
93 backspace to where we started. */
95 write_record (int move_back_flag
)
97 union block
*save_record
= record_start
;
98 record_start
= new_record
;
100 if (acting_as_filter
)
102 archive
= STDOUT_FILENO
;
104 archive
= STDIN_FILENO
;
108 move_archive ((records_written
+ records_skipped
) - records_read
);
112 record_start
= save_record
;
116 /* Move the tape head back to where we were. */
118 if (! acting_as_filter
)
119 move_archive (records_read
- (records_written
+ records_skipped
));
126 write_recent_blocks (union block
*h
, size_t blocks
)
129 for (i
= 0; i
< blocks
; i
++)
131 new_record
[new_blocks
++] = h
[i
];
132 if (new_blocks
== blocking_factor
)
138 delete_archive_members (void)
140 enum read_header logical_status
= HEADER_STILL_UNREAD
;
141 enum read_header previous_status
= HEADER_STILL_UNREAD
;
143 /* FIXME: Should clean the routine before cleaning these variables :-( */
145 off_t blocks_to_skip
= 0;
146 off_t blocks_to_keep
= 0;
147 int kept_blocks_in_record
;
150 open_archive (ACCESS_UPDATE
);
151 acting_as_filter
= strcmp (archive_name_array
[0], "-") == 0;
155 enum read_header status
= read_header (1);
159 case HEADER_STILL_UNREAD
:
163 if (name
= name_scan (current_file_name
), !name
)
170 case HEADER_SUCCESS_EXTENDED
:
171 logical_status
= status
;
174 case HEADER_ZERO_BLOCK
:
175 if (ignore_zeros_option
)
177 set_next_block_after (current_header
);
181 case HEADER_END_OF_FILE
:
182 logical_status
= HEADER_END_OF_FILE
;
186 set_next_block_after (current_header
);
187 switch (previous_status
)
189 case HEADER_STILL_UNREAD
:
190 WARN ((0, 0, _("This does not look like a tar archive")));
194 case HEADER_ZERO_BLOCK
:
195 ERROR ((0, 0, _("Skipping to next header")));
201 case HEADER_END_OF_FILE
:
207 previous_status
= status
;
209 while (logical_status
== HEADER_STILL_UNREAD
);
211 records_skipped
= records_read
- 1;
212 new_record
= xmalloc (record_size
);
214 if (logical_status
== HEADER_SUCCESS
215 || logical_status
== HEADER_SUCCESS_EXTENDED
)
217 write_archive_to_stdout
= 0;
219 /* Save away blocks before this one in this record. */
221 new_blocks
= current_block
- record_start
;
223 memcpy (new_record
, record_start
, new_blocks
* BLOCKSIZE
);
225 if (logical_status
== HEADER_SUCCESS
)
227 /* FIXME: Pheew! This is crufty code! */
228 logical_status
= HEADER_STILL_UNREAD
;
232 /* FIXME: Solaris 2.4 Sun cc (the ANSI one, not the old K&R) says:
233 "delete.c", line 223: warning: loop not entered at top
234 Reported by Bruno Haible. */
237 enum read_header status
;
239 /* Fill in a record. */
241 if (current_block
== record_end
)
243 status
= read_header (0);
245 if (status
== HEADER_ZERO_BLOCK
&& ignore_zeros_option
)
247 set_next_block_after (current_header
);
250 if (status
== HEADER_END_OF_FILE
|| status
== HEADER_ZERO_BLOCK
)
252 logical_status
= HEADER_END_OF_FILE
;
256 if (status
== HEADER_FAILURE
)
258 ERROR ((0, 0, _("Deleting non-header from archive")));
259 set_next_block_after (current_header
);
263 /* Found another header. */
265 if (name
= name_scan (current_file_name
), name
)
269 set_next_block_after (current_header
);
270 blocks_to_skip
= (current_stat
.st_size
+ BLOCKSIZE
- 1) / BLOCKSIZE
;
272 while (record_end
- current_block
<= blocks_to_skip
)
274 blocks_to_skip
-= (record_end
- current_block
);
277 current_block
+= blocks_to_skip
;
284 write_recent_blocks (recent_long_name
, recent_long_name_blocks
);
285 write_recent_blocks (recent_long_link
, recent_long_link_blocks
);
286 new_record
[new_blocks
] = *current_header
;
289 = (current_stat
.st_size
+ BLOCKSIZE
- 1) / BLOCKSIZE
;
290 set_next_block_after (current_header
);
291 if (new_blocks
== blocking_factor
)
296 kept_blocks_in_record
= record_end
- current_block
;
297 if (kept_blocks_in_record
> blocks_to_keep
)
298 kept_blocks_in_record
= blocks_to_keep
;
300 while (blocks_to_keep
)
304 if (current_block
== record_end
)
307 current_block
= record_start
;
308 kept_blocks_in_record
= blocking_factor
;
309 if (kept_blocks_in_record
> blocks_to_keep
)
310 kept_blocks_in_record
= blocks_to_keep
;
312 count
= kept_blocks_in_record
;
313 if (blocking_factor
- new_blocks
< count
)
314 count
= blocking_factor
- new_blocks
;
319 memcpy (new_record
+ new_blocks
, current_block
, count
* BLOCKSIZE
);
321 current_block
+= count
;
322 blocks_to_keep
-= count
;
323 kept_blocks_in_record
-= count
;
325 if (new_blocks
== blocking_factor
)
331 if (logical_status
== HEADER_END_OF_FILE
)
333 /* Write the end of tape. FIXME: we can't use write_eot here,
334 as it gets confused when the input is at end of file. */
336 int total_zero_blocks
= 0;
340 int zero_blocks
= blocking_factor
- new_blocks
;
341 memset (new_record
+ new_blocks
, 0, BLOCKSIZE
* zero_blocks
);
342 total_zero_blocks
+= zero_blocks
;
343 write_record (total_zero_blocks
< 2);
345 while (total_zero_blocks
< 2);
350 if (! acting_as_filter
&& ! _isrmt (archive
))
353 int status
= write (archive
, "", 0);
355 off_t pos
= lseek (archive
, (off_t
) 0, SEEK_CUR
);
356 int status
= pos
< 0 ? -1 : ftruncate (archive
, pos
);
359 truncate_warn (archive_name_array
[0]);