#! /usr/bin/perl -w
use strict;
my @program1 = `perl ./hello.pl`;
foreach (@program1) {
  # pass to program2
  &program2($_);
}

sub program2() {
  # value from program1
  my $value = shift;
  my @newvalue = `echo $value | perl ./chopup.pl`;
  foreach (@newvalue) {
     print $_;
   }
}