#! /bin/sh
# Usage: tarcat volume1 volume2 ...
# concatenates a GNU tar multi-volume archive into a single tar archive.
-# Author: Bruno Haible <bruno@clisp.org>
+# Author: Bruno Haible <bruno@clisp.org>, Sergey Poznyakoff <gray@gnu.org.ua>
+
+# Copyright 2004-2005, 2010, 2013 Free Software Foundation, Inc.
+
+# This file is part of GNU tar.
+
+# GNU tar 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 3 of the License, or
+# (at your option) any later version.
+
+# GNU tar 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, see <http://www.gnu.org/licenses/>.
+
+# dump_type FILE [N]
+# Print type character from block N (default 0) of tar archive FILE
+dump_type() {
+ dd if="$1" skip=${2:-0} bs=512 count=1 2>/dev/null |
+ tr '\0' ' ' |
+ cut -c157
+}
+
+case `dump_type "$1"` in
+ [gx]) PAX=1;;
+esac
cat "$1"
shift
for f
do
- dd skip=1 if="$f"
+ SKIP=0
+ T=`dump_type "$f"`
+ if [ -n "$PAX" ]; then
+ if [ "$T" = "g" ]; then
+ # Global extended header.... 2 blocks
+ # Extended header........... 2 blocks
+ # Ustar header.............. 1 block
+ # FIXME: This calculation is will fail for very long file names.
+ SKIP=5
+ fi
+ else
+ if [ "$T" = "V" ]; then
+ T=`dump_type "$f" 1`
+ fi
+ if [ "$T" = "M" ]; then
+ SKIP=$(($SKIP + 1))
+ fi
+ fi
+ dd skip=$SKIP if="$f"
done