#! /usr/bin/perl
`( sudo pgp -e test_file.dat 0x57A59396 >& /dev/null ) >& /dev/null` ;
`sudo chown sgov test_file.dat.pgp` ;
`sudo chgrp users test_file.dat.pgp` ;
[download]

Note that the path to perl might be different for you

LuCa