A tiny sharfile generator that uses base64 to encode/decode (for redhat Linux; base64 is in coreutils, which is an rpm prerequisite so it's more likely to always be there)

mkshar.sh

#! /bin/sh
#
# mkshar: make a shar file 
#

usage() {
    echo "usage: $0 [--rc file] payload [...]" 1>&2
    exit 1
}

unset checksums

case X"$1" in
X-rc|X--rc)	rc=$2
		shift 2 ;;
X-md5|X--md5)   checksums=Y
		shift ;;
X-*)		usage ;;
esac

cat - << \EOF
#! /bin/sh
# self extracting archive

# make a tempfile, go there to do the work
DEST=`mktemp -d /tmp/sb.XXXXXX`

test "$DEST" || exit 1

trap "cd /tmp; rm -rf $DEST" 1 2 3 9 15

cd $DEST || exit 1

EOF


# encode all the input files into base64, set up the script
# to unpack them into their basename in this directory

seq=1
for file in "$@"; do
    echo
    echo "# $seq: $file"
    echo "base64 -d > `basename $file` << \EOF"
    base64 "$file"
    echo EOF 
    (( seq ++ ))
done

# want to do something with this tarball?   Hope so!
if [ "$rc" ]; then
    echo
    echo "# process everything now that we're done with it"
    cat "$rc"
elif [ "$checksums" ]; then
    echo
    echo 'md5sum *'
fi

cat - << \EOF

# clean up after we're finished
cd /tmp
rm -rf $DEST
EOF

echo "exit 0"

exit 0