while(1){
    my $var = &foo() ;
    ...
  }

##</code><code>##

  perl -wle'my $last; while (my $line = <STDIN>) { last if $line =~ /^$/; print \$line; $last = \$line; }'

##</code><code>##

  sub foo { print shift }
  sub bar { &foo; print @_ } # BAD!