Script that creates self extracting executable script from tar.gz file.

selftar.sh

#!/bin/sh


if [ $# -eq 0 ]; then
        echo "This script creates self extractable executable"
        echo Usage: $0 TAR.GZ [COMMAND]
        exit;
fi
if [ $# -gt 0 ]; then
        TAR_FILE=$1
fi
EXIT_COMMAND=exit
if [ $# -gt 1 ]; then
        EXIT_COMMAND="exec $2"
fi

SELF_EXTRACTABLE="$TAR_FILE.self"

echo '#!/bin/sh' > $SELF_EXTRACTABLE
echo 'dd bs=1 skip=`head -3 $0 | wc -c`  if=$0  | gunzip -c  | tar -x' >> $SELF_EXTRACTABLE
echo "$EXIT_COMMAND" >> $SELF_EXTRACTABLE

cat $TAR_FILE >> $SELF_EXTRACTABLE
chmod a+x $SELF_EXTRACTABLE

Thanks Alex, works very well.