GNU tar 1.12
This commit is contained in:
Paul Eggert
336
src/delete.c
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336
src/delete.c
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/* Delete entries from a tar archive.
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Copyright (C) 1988, 1992, 1994, 1996, 1997 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2, or (at your option) any later
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version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
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Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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59 Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "system.h"
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#define STDIN 0
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#define STDOUT 1
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#include "common.h"
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#include "rmt.h"
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static union block *new_record = NULL;
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static union block *save_record = NULL;
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static int records_read = 0;
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static int new_blocks = 0;
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static int blocks_needed = 0;
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/* FIXME: This module should not directly handle the following three
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variables, instead, this should be done in buffer.c only. */
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extern union block *record_start;
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extern union block *record_end;
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extern union block *current_block;
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/*-------------------------------------------------------------------------.
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| Move archive descriptor by COUNT records worth. If COUNT is positive we |
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| move forward, else we move negative. If its a tape, MTIOCTOP had better |
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| work. If its something else, we try to seek on it. If we can't seek, |
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| we loose! |
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`-------------------------------------------------------------------------*/
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static void
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move_archive (int count)
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{
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#ifdef MTIOCTOP
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{
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struct mtop operation;
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int status;
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if (count > 0)
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{
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operation.mt_op = MTFSR;
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operation.mt_count = count;
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}
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else
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{
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operation.mt_op = MTBSR;
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operation.mt_count = -count;
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}
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if (status = rmtioctl (archive, MTIOCTOP, (char *) &operation),
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status >= 0)
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return;
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if (errno == EIO)
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if (status = rmtioctl (archive, MTIOCTOP, (char *) &operation),
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status >= 0)
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return;
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}
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#endif /* MTIOCTOP */
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{
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off_t position = rmtlseek (archive, 0L, 1);
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position += record_size * count;
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if (rmtlseek (archive, position, 0) != position)
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FATAL_ERROR ((0, 0, _("Could not re-position archive file")));
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return;
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}
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}
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/*----------------------------------------------------------------.
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| Write out the record which has been filled. If MOVE_BACK_FLAG, |
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| backspace to where we started. |
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`----------------------------------------------------------------*/
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static void
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write_record (int move_back_flag)
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{
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save_record = record_start;
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record_start = new_record;
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if (archive == STDIN)
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{
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archive = STDOUT;
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flush_write ();
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archive = STDIN;
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}
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else
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{
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move_archive (-(records_read + 1));
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flush_write ();
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}
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record_start = save_record;
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if (move_back_flag)
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{
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/* Move the tape head back to where we were. */
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if (archive != STDIN)
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move_archive (records_read);
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records_read--;
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}
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blocks_needed = blocking_factor;
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new_blocks = 0;
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}
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/*---.
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| ? |
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`---*/
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void
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delete_archive_members (void)
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{
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enum read_header logical_status = HEADER_STILL_UNREAD;
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enum read_header previous_status = HEADER_STILL_UNREAD;
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/* FIXME: Should clean the routine before cleaning these variables :-( */
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struct name *name;
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int blocks_to_skip = 0;
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int blocks_to_keep = 0;
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int kept_blocks_in_record;
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name_gather ();
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open_archive (ACCESS_UPDATE);
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while (logical_status == HEADER_STILL_UNREAD)
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{
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enum read_header status = read_header ();
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switch (status)
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{
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case HEADER_STILL_UNREAD:
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abort ();
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case HEADER_SUCCESS:
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if (name = name_scan (current_file_name), !name)
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{
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set_next_block_after (current_header);
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if (current_header->oldgnu_header.isextended)
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skip_extended_headers ();
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skip_file ((long) (current_stat.st_size));
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break;
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}
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name->found = 1;
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logical_status = HEADER_SUCCESS;
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break;
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case HEADER_ZERO_BLOCK:
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case HEADER_END_OF_FILE:
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logical_status = HEADER_END_OF_FILE;
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break;
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case HEADER_FAILURE:
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set_next_block_after (current_header);
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switch (previous_status)
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{
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case HEADER_STILL_UNREAD:
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WARN ((0, 0, _("This does not look like a tar archive")));
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/* Fall through. */
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case HEADER_SUCCESS:
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case HEADER_ZERO_BLOCK:
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ERROR ((0, 0, _("Skipping to next header")));
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/* Fall through. */
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case HEADER_FAILURE:
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break;
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case HEADER_END_OF_FILE:
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abort ();
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}
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break;
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}
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previous_status = status;
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}
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if (logical_status != HEADER_SUCCESS)
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{
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write_eot ();
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close_archive ();
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names_notfound ();
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return;
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}
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write_archive_to_stdout = 0;
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new_record = (union block *) xmalloc ((size_t) record_size);
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/* Save away blocks before this one in this record. */
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new_blocks = current_block - record_start;
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blocks_needed = blocking_factor - new_blocks;
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if (new_blocks)
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memcpy ((void *) new_record, (void *) record_start,
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(size_t) (new_blocks * BLOCKSIZE));
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#if 0
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/* FIXME: Old code, before the goto was inserted. To be redesigned. */
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set_next_block_after (current_header);
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if (current_header->oldgnu_header.isextended)
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skip_extended_headers ();
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skip_file ((long) (current_stat.st_size));
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#endif
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logical_status = HEADER_STILL_UNREAD;
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goto flush_file;
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/* FIXME: Solaris 2.4 Sun cc (the ANSI one, not the old K&R) says:
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"delete.c", line 223: warning: loop not entered at top
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Reported by Bruno Haible. */
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while (1)
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{
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enum read_header status;
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/* Fill in a record. */
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if (current_block == record_end)
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{
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flush_archive ();
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records_read++;
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}
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status = read_header ();
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if (status == HEADER_ZERO_BLOCK && ignore_zeros_option)
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{
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set_next_block_after (current_header);
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continue;
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}
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if (status == HEADER_END_OF_FILE || status == HEADER_ZERO_BLOCK)
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{
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logical_status = HEADER_END_OF_FILE;
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memset (new_record[new_blocks].buffer, 0,
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(size_t) (BLOCKSIZE * blocks_needed));
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new_blocks += blocks_needed;
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blocks_needed = 0;
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write_record (0);
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break;
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}
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if (status == HEADER_FAILURE)
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{
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ERROR ((0, 0, _("Deleting non-header from archive")));
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set_next_block_after (current_header);
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continue;
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}
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/* Found another header. */
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if (name = name_scan (current_file_name), name)
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{
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name->found = 1;
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flush_file:
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set_next_block_after (current_header);
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blocks_to_skip = (current_stat.st_size + BLOCKSIZE - 1) / BLOCKSIZE;
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while (record_end - current_block <= blocks_to_skip)
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{
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blocks_to_skip -= (record_end - current_block);
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flush_archive ();
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records_read++;
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}
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current_block += blocks_to_skip;
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blocks_to_skip = 0;
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continue;
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}
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/* Copy header. */
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new_record[new_blocks] = *current_header;
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new_blocks++;
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blocks_needed--;
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blocks_to_keep
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= (current_stat.st_size + BLOCKSIZE - 1) / BLOCKSIZE;
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set_next_block_after (current_header);
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if (blocks_needed == 0)
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write_record (1);
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/* Copy data. */
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kept_blocks_in_record = record_end - current_block;
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if (kept_blocks_in_record > blocks_to_keep)
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kept_blocks_in_record = blocks_to_keep;
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while (blocks_to_keep)
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{
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int count;
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if (current_block == record_end)
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{
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flush_read ();
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records_read++;
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current_block = record_start;
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kept_blocks_in_record = blocking_factor;
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if (kept_blocks_in_record > blocks_to_keep)
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kept_blocks_in_record = blocks_to_keep;
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}
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count = kept_blocks_in_record;
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if (count > blocks_needed)
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count = blocks_needed;
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memcpy ((void *) (new_record + new_blocks),
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(void *) current_block,
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(size_t) (count * BLOCKSIZE));
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new_blocks += count;
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blocks_needed -= count;
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current_block += count;
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blocks_to_keep -= count;
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kept_blocks_in_record -= count;
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if (blocks_needed == 0)
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write_record (1);
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}
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}
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write_eot ();
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close_archive ();
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names_notfound ();
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}
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