#!/usr/bin/perl -w
 
use strict;
 
my $uclc    = shift or Usage();
my $infile  = shift or Usage();
my $outfile = shift or Usage();
Usage() unless ($uclc eq 'lc' || $uclc eq 'uc');
 
open (IN, "< $infile") or die "Error opening $infile for read: $!";
open (OUT, "> $outfile") or die "Error opening $outfile for write: $!";

foreach (<IN>) {
  # just print directly on reading, easier on the mem..
  #  quicker too, and we know that $uclc is going to 
  #  be either lc or uc at this point.
  print OUT $uclc eq 'lc' ? lc() : uc();
}
 
close IN               or die "Error closing $infile after read: $!";
close OUT                or die "Error closing $outfile after write: $!";
 
##########################################################################
sub Usage {
   die "\n Usage: uclc.pl (lc|uc) infile outfile\n";
   }
##########################################################################