for (my $i = 0; $i < $num; $i++) {
   print "$ARGV[$i]\n";
   open (FH, "$ARGV[$i]") || die "Cant open: $!";
   while (<FH>) {
     chomp;  ## <- added this line
     push @out, lc;
   }
   close FH || die "Cant open: $!";
}

##</code><code>##

print join (@out,"\n");