def main(pattern|p=s, (lines|n=i), make-uppercase|u, (junk|j=s "junk default")) : template {
  [% IF junk == "junk default" %]
    grep -v "^${pattern}$" | my_head -n $lines
                                     [% IF make_uppercase %] --make-uppercase [% END %]
  [% ELSE %]
    echo [% junk %]
  [% END %]
}


def my_head(n|lines=i, u|make-uppercase) : template {
  head -n [% n || 5 %]

  [% IF u %]
    | uppercase-it
  [% END %]
}


def uppercase-it : perl -ne {
  print uc
}