From: Paul Eggert Date: Fri, 25 Apr 1997 17:10:08 +0000 (+0000) Subject: GNU tar 1.12 X-Git-Url: https://git.dogcows.com/gitweb?a=commitdiff_plain;h=3e3d9b7e3962df782fd733ea9dd2fe2be37f58d6;p=chaz%2Ftar GNU tar 1.12 --- diff --git a/src/delete.c b/src/delete.c new file mode 100644 index 0000000..4cb73b3 --- /dev/null +++ b/src/delete.c @@ -0,0 +1,336 @@ +/* Delete entries from a tar archive. + Copyright (C) 1988, 1992, 1994, 1996, 1997 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by the + Free Software Foundation; either version 2, or (at your option) any later + version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General + Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 59 Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#include "system.h" + +#define STDIN 0 +#define STDOUT 1 + +#include "common.h" +#include "rmt.h" + +static union block *new_record = NULL; +static union block *save_record = NULL; +static int records_read = 0; +static int new_blocks = 0; +static int blocks_needed = 0; + +/* FIXME: This module should not directly handle the following three + variables, instead, this should be done in buffer.c only. */ +extern union block *record_start; +extern union block *record_end; +extern union block *current_block; + +/*-------------------------------------------------------------------------. +| Move archive descriptor by COUNT records worth. If COUNT is positive we | +| move forward, else we move negative. If its a tape, MTIOCTOP had better | +| work. If its something else, we try to seek on it. If we can't seek, | +| we loose! | +`-------------------------------------------------------------------------*/ + +static void +move_archive (int count) +{ +#ifdef MTIOCTOP + { + struct mtop operation; + int status; + + if (count > 0) + { + operation.mt_op = MTFSR; + operation.mt_count = count; + } + else + { + operation.mt_op = MTBSR; + operation.mt_count = -count; + } + + if (status = rmtioctl (archive, MTIOCTOP, (char *) &operation), + status >= 0) + return; + + if (errno == EIO) + if (status = rmtioctl (archive, MTIOCTOP, (char *) &operation), + status >= 0) + return; + } +#endif /* MTIOCTOP */ + + { + off_t position = rmtlseek (archive, 0L, 1); + + position += record_size * count; + + if (rmtlseek (archive, position, 0) != position) + FATAL_ERROR ((0, 0, _("Could not re-position archive file"))); + + return; + } +} + +/*----------------------------------------------------------------. +| Write out the record which has been filled. If MOVE_BACK_FLAG, | +| backspace to where we started. | +`----------------------------------------------------------------*/ + +static void +write_record (int move_back_flag) +{ + save_record = record_start; + record_start = new_record; + + if (archive == STDIN) + { + archive = STDOUT; + flush_write (); + archive = STDIN; + } + else + { + move_archive (-(records_read + 1)); + flush_write (); + } + + record_start = save_record; + + if (move_back_flag) + { + /* Move the tape head back to where we were. */ + + if (archive != STDIN) + move_archive (records_read); + + records_read--; + } + + blocks_needed = blocking_factor; + new_blocks = 0; +} + +/*---. +| ? | +`---*/ + +void +delete_archive_members (void) +{ + enum read_header logical_status = HEADER_STILL_UNREAD; + enum read_header previous_status = HEADER_STILL_UNREAD; + + /* FIXME: Should clean the routine before cleaning these variables :-( */ + struct name *name; + int blocks_to_skip = 0; + int blocks_to_keep = 0; + int kept_blocks_in_record; + + name_gather (); + open_archive (ACCESS_UPDATE); + + while (logical_status == HEADER_STILL_UNREAD) + { + enum read_header status = read_header (); + + switch (status) + { + case HEADER_STILL_UNREAD: + abort (); + + case HEADER_SUCCESS: + if (name = name_scan (current_file_name), !name) + { + set_next_block_after (current_header); + if (current_header->oldgnu_header.isextended) + skip_extended_headers (); + skip_file ((long) (current_stat.st_size)); + break; + } + name->found = 1; + logical_status = HEADER_SUCCESS; + break; + + case HEADER_ZERO_BLOCK: + case HEADER_END_OF_FILE: + logical_status = HEADER_END_OF_FILE; + break; + + case HEADER_FAILURE: + set_next_block_after (current_header); + switch (previous_status) + { + case HEADER_STILL_UNREAD: + WARN ((0, 0, _("This does not look like a tar archive"))); + /* Fall through. */ + + case HEADER_SUCCESS: + case HEADER_ZERO_BLOCK: + ERROR ((0, 0, _("Skipping to next header"))); + /* Fall through. */ + + case HEADER_FAILURE: + break; + + case HEADER_END_OF_FILE: + abort (); + } + break; + } + + previous_status = status; + } + + if (logical_status != HEADER_SUCCESS) + { + write_eot (); + close_archive (); + names_notfound (); + return; + } + + write_archive_to_stdout = 0; + new_record = (union block *) xmalloc ((size_t) record_size); + + /* Save away blocks before this one in this record. */ + + new_blocks = current_block - record_start; + blocks_needed = blocking_factor - new_blocks; + if (new_blocks) + memcpy ((void *) new_record, (void *) record_start, + (size_t) (new_blocks * BLOCKSIZE)); + +#if 0 + /* FIXME: Old code, before the goto was inserted. To be redesigned. */ + set_next_block_after (current_header); + if (current_header->oldgnu_header.isextended) + skip_extended_headers (); + skip_file ((long) (current_stat.st_size)); +#endif + logical_status = HEADER_STILL_UNREAD; + goto flush_file; + + /* FIXME: Solaris 2.4 Sun cc (the ANSI one, not the old K&R) says: + "delete.c", line 223: warning: loop not entered at top + Reported by Bruno Haible. */ + while (1) + { + enum read_header status; + + /* Fill in a record. */ + + if (current_block == record_end) + { + flush_archive (); + records_read++; + } + status = read_header (); + + if (status == HEADER_ZERO_BLOCK && ignore_zeros_option) + { + set_next_block_after (current_header); + continue; + } + if (status == HEADER_END_OF_FILE || status == HEADER_ZERO_BLOCK) + { + logical_status = HEADER_END_OF_FILE; + memset (new_record[new_blocks].buffer, 0, + (size_t) (BLOCKSIZE * blocks_needed)); + new_blocks += blocks_needed; + blocks_needed = 0; + write_record (0); + break; + } + + if (status == HEADER_FAILURE) + { + ERROR ((0, 0, _("Deleting non-header from archive"))); + set_next_block_after (current_header); + continue; + } + + /* Found another header. */ + + if (name = name_scan (current_file_name), name) + { + name->found = 1; + flush_file: + set_next_block_after (current_header); + blocks_to_skip = (current_stat.st_size + BLOCKSIZE - 1) / BLOCKSIZE; + + while (record_end - current_block <= blocks_to_skip) + { + blocks_to_skip -= (record_end - current_block); + flush_archive (); + records_read++; + } + current_block += blocks_to_skip; + blocks_to_skip = 0; + continue; + } + + /* Copy header. */ + + new_record[new_blocks] = *current_header; + new_blocks++; + blocks_needed--; + blocks_to_keep + = (current_stat.st_size + BLOCKSIZE - 1) / BLOCKSIZE; + set_next_block_after (current_header); + if (blocks_needed == 0) + write_record (1); + + /* Copy data. */ + + kept_blocks_in_record = record_end - current_block; + if (kept_blocks_in_record > blocks_to_keep) + kept_blocks_in_record = blocks_to_keep; + + while (blocks_to_keep) + { + int count; + + if (current_block == record_end) + { + flush_read (); + records_read++; + current_block = record_start; + kept_blocks_in_record = blocking_factor; + if (kept_blocks_in_record > blocks_to_keep) + kept_blocks_in_record = blocks_to_keep; + } + count = kept_blocks_in_record; + if (count > blocks_needed) + count = blocks_needed; + + memcpy ((void *) (new_record + new_blocks), + (void *) current_block, + (size_t) (count * BLOCKSIZE)); + new_blocks += count; + blocks_needed -= count; + current_block += count; + blocks_to_keep -= count; + kept_blocks_in_record -= count; + + if (blocks_needed == 0) + write_record (1); + } + } + + write_eot (); + close_archive (); + names_notfound (); +}