UNIVERSAL::require(3pm) - phpMan

UNIVERSAL::require(3pm)        User Contributed Perl Documentation        UNIVERSAL::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 AT 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 AT 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 v5.32.1                                2021-09-05                    UNIVERSAL::require(3pm)

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