sub GROOMLDIF {
    # Delete LDAP-internal fields
    my @erasethese = qw(
        structuralObjectClass
        entryUUID
        creatorsName
        modifiersName
        createTimestamp
        modifyTimestamp
        entryCSN
    );
   
    open my $fh_in , '<', "data/all.ldif"     or die "can not open data/all.ldif: $!";
    open my $fh_out, '>', "data/groomed.ldif" or die "can not open data/groomed.ldif: $!";
    while (<$fh_in>) {
        my $line = $_;
        my @thing = (split /:/)[0];
        print $fh_out $line unless (grep {$thing eq $_} @erasethese);
    }
}