UNIVERSAL::require(3pmUser Contributed Perl DocumentatiUNIVERSAL::require(3pm)
NAME
UNIVERSAL::require - require() modules from a variable [deprecated]
SYNOPSIS
# This only needs to be said once in your program.
require UNIVERSAL::require;
# Same as "require Some::Module"
my $module = 'Some::Module';
$module->require or die $@;
# Same as "use Some::Module"
BEGIN { $module->use or die $@ }
DESCRIPTION
Before using this module, you should look at the alternatives, some of
which are listed in SEE ALSO below.
This module provides a safe mechanism for loading a module at runtime,
when you have the name of the module in a variable.
If you've ever had to do this...
eval "require $module";
to get around the bareword caveats on require(), this module is for
you. It creates a universal require() class method that will work with
every Perl module and its secure. So instead of doing some arcane
eval() work, you can do this:
$module->require;
It doesn't save you much typing, but it'll make a lot more sense to
someone who's not a ninth level Perl acolyte.
Methods
require
my $return_val = $module->require or die $@;
my $return_val = $module->require($version) or die $@;
This works exactly like Perl's require, except without the bareword
restriction, and it doesn't die. Since require() is placed in the
UNIVERSAL namespace, it will work on any module. You just have to use
UNIVERSAL::require somewhere in your code.
Should the module require fail, or not be a high enough $version, it
will simply return false and not die. The error will be in $@ as well
as $UNIVERSAL::require::ERROR.
$module->require or die $@;
use
my $require_return = $module->use or die $@;
my $require_return = $module->use(@imports) or die $@;
Like "UNIVERSAL::require", this allows you to "use" a $module without
having to eval to work around the bareword requirement. It returns the
same as require.
Should either the require or the import fail it will return false. The
error will be in $@.
If possible, call this inside a BEGIN block to emulate a normal "use"
as closely as possible.
BEGIN { $module->use }
SECURITY NOTES
UNIVERSAL::require makes use of "eval STRING". In previous versions of
UNIVERSAL::require it was discovered that one could craft a class name
which would result in code being executed. This hole has been closed.
The only variables now exposed to "eval STRING" are the caller's
package, filename and line which are not tainted.
UNIVERSAL::require is taint clean.
COPYRIGHT
Copyright 2001, 2005 by Michael G Schwern <schwern@pobox.com>.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See http://www.perl.com/perl/misc/Artistic.html
AUTHOR
Michael G Schwern <schwern@pobox.com>
Now maintained by Neil Bowers (NEILB).
SEE ALSO
Module::Load provides functions for loading code, and importing
functions. It's actively maintained.
Module::Runtime provides a number of usesful functions for require'ing
and use'ing modules, and associated operations.
Mojo::Loader is a class loader and plugin framework. Module::Loader is
a stand-alone module that was inspired by "Mojo::Loader".
There are many other modules that may be of interest on CPAN. An old
review of some of them can be read at
<https://neilb.org/reviews/module-loading.html>.
"require" in perlfunc.
perl v5.36.0 2022-11-19 UNIVERSAL::require(3pm)
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