# Encode
    perl -le 'print join " ", map {ord pack "H2", $_} shift =~ /../g' num

    # decode
    perl -le 'print unpack "H*", pack "C*", @ARGV'  num1 num2 ...

    perl -le 'print map {int($_/16).($_%16)} @ARGV' num1 num2 ...



##</code><code>##

    # Encode

    $ perl -le 'print join " ", map {ord pack "H2", $_} shift =~ /../g' 019774
    1 151 116


    # decode

    $ perl -le 'print unpack "H*", pack "C*", @ARGV' 1 151 116
    019774