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less(3perl) Perl Programmers Reference Guide less(3perl)


less - perl pragma to request less of something


    use less 'CPU';


This is a user-pragma. If you're very lucky some code you're using will know that you asked for less CPU usage or ram or fat or... we just can't know. Consult your documentation on everything you're currently using.

For general suggestions, try requesting "CPU" or "memory".

    use less 'memory';
    use less 'CPU';
    use less 'fat';

If you ask for nothing in particular, you'll be asking for less 'please'.

    use less 'please';


less has been in the core as a "joke" module for ages now and it hasn't had any real way to communicating any information to anything. Thanks to Nicholas Clark we have user pragmas (see perlpragma) and now "less" can do something.

You can probably expect your users to be able to guess that they can request less CPU or memory or just "less" overall.

If the user didn't specify anything, it's interpreted as having used the "please" tag. It's up to you to make this useful.

  # equivalent
  use less;
  use less 'please';

"BOOLEAN = less->of( FEATURE )"

The class method "less->of( NAME )" returns a boolean to tell you whether your user requested less of something.

  if ( less->of( 'CPU' ) ) {
  elsif ( less->of( 'memory' ) ) {

"FEATURES = less->of()"

If you don't ask for any feature, you get the list of features that the user requested you to be nice to. This has the nice side effect that if you don't respect anything in particular then you can just ask for it and use it like a boolean.

  if ( less->of ) {
  else {


At least it's backwards compatible in not doing much.
2024-05-30 perl v5.38.2