sub remove_cruft
{
  # do stuff to single line $_[0];
}
# use as:
while (my $l = <$fh>)
{
  remove_cruft($l);
  remove_other_cruft($l);
  remove_yet_more_cruft($l);

  # or ...
  $_->($l) foreach (\&remove_cruft, \&remove_other_cruft, \&remove_yet_more_cruft);

}