Select Code to Download

open my $pipe, "foobar|" or die "$!\n";
print frobnicate( $_ ) while <$pipe>:

{
  open my $in, 'foo.tsv' or die "$!\n";
...
  open my $out, '>', 'foo_view.tsv' or die "$!\n";
  print $out $_ for sort @records;
}

{
  open my $in, 'foo.tsv' or die "$!\n";
...
  open my $out, '>', 'foo_view.tsv' or die "$!\n";
  print $out $_ while <$in>;
}

sub sortit {
  my ( $fh ) = shift;
...
  print $pipe $_ while <$fh>;
  exit 0;
}

sub grepit {
  my ( $fh, $keep ) = @_;
...
    while <$fh>;
  exit 0;
}