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UNIVERSAL::require(3)                User Contributed Perl Documentation               UNIVERSAL::require(3)



NAME
       UNIVERSAL::require - require() modules from a variable

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
       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 alot 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>

SEE ALSO
       Module::Load,  "require" in perlfunc, <http://dev.perl.org/rfc/253.pod>



perl v5.16.2                                     2009-03-30                            UNIVERSAL::require(3)