Problem with tar in a backup script

Shell Programming and Scripting
1

I had an idea of very-very easy bacup script that packs ALL of the files in current dir (including the subfulders and with spaces in name), packs them with tar+gz and moves to a directory. I'm using Cywin under WinXP.
But I have a problem with tar. When I do in a single line

"tar -rf "backup.tar" "somefile1.txt"; "tar -rf "backup.tar" "somefile2.txt";

It says that I need -M for multiple archives (?).
That's my code:

#!/bin/sh
BackUpDir="/cygdrive/D/Backup5"
if ([ $1 ]) then
  BackUpDir=$1
fi
if ([ ! -d $BackUpDir ]) then
  mkdir -pv $BackUpDir
fi
ArchiveName="$BackUpDir/"`date +"%d.%m.%y(%H.%M)"``dirs | sed 's!^\(/\?.*\)*/\(.*\)$!\2!g'`".tar"
PackCommand=`find -type f -regex ^.*$ | sed 's!^\(.*\)$!tar -M -rf \"__tmp.tar\" \"\1\"'!g`
$PackCommand
rm "__tmp.tar" $ArchiveName
gzip $ArchiveName
2

Why do you have so many double quotes in that line? Try without them maybe. Does it work with -M? In you code you are using -M. What happens if both tar's are being executed on separate lines?
I did not check your sed's but tar takes anything from the starting directory for example, that you want even files that have blanks in etc. Not sure if cygwin's tar is making a difference.

3

I've did some experiments with masks for tar - tar -cd "$ArchiveName" * works fine and includes subdirectories as well.
Anyway, that's a final verusion of my script. It bacups the current folder, including names with spaces and subdirectories.