less(3pm) Perl Programmers Reference Guide less(3pm)
NAME
less - perl pragma to request less of something
SYNOPSIS
use less 'CPU';
DESCRIPTION
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';
FOR MODULE AUTHORS
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 {
...
}
CAVEATS
This probably does nothing.
This works only on 5.10+
At least it's backwards compatible in not doing much.
perl v5.26.3 2018-03-01 less(3pm)