#!/usr/bin/perl -w
use strict;
unless ($ARGV[0] eq '-lc' || $ARGV[0] eq '-uc' ){
	die "usage: lcuc [-uc | -lc] file\n";
}

my $op = substr(shift @ARGV, 1, 2);

while(<>){
	no strict 'refs';
	print &{$op}($_)
}

sub lc{ lc shift }
sub uc{ uc shift }

##</code><code>##

#!/usr/bin/perl -w
use strict;

my %ops = (
	'lc' => sub {lc shift },
	'uc' => sub {uc shift },
);


my $case = shift @ARGV;
unless (exists $ops{$case}){
	die "usage: lcuc [", join(' | ', keys %ops), "] file\n";
}
while(<>){
	print $ops{$case}->($_);
}