# 1

#!/usr/bin/perl -w
use strict;
my $other_program = 'echo';
while(<>){
    chomp;
    system($other_program, $_);
}
__END__



# 2

#!/usr/bin/perl -w
use strict;
my $other_program = 'tr [a-z] [A-Z]';
open(OTHER, "|$other_program") || die "Kant: $!";
while(<>){
    print OTHER $_;
}
close OTHER;
__END__