UNIVERSAL::require(3pm)

1UNIVERSAL::require(3) User Contributed Perl DocumentationUNIVERSAL::require(3)
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NAME

6       UNIVERSAL::require - require() modules from a variable [deprecated]
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SYNOPSIS

9         # This only needs to be said once in your program.
10         require UNIVERSAL::require;
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12         # Same as "require Some::Module"
13         my $module = 'Some::Module';
14         $module->require or die $@;
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16         # Same as "use Some::Module"
17         BEGIN { $module->use or die $@ }
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DESCRIPTION

20       Before using this module, you should look at the alternatives, some of
21       which are listed in SEE ALSO below.
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23       This module provides a safe mechanism for loading a module at runtime,
24       when you have the name of the module in a variable.
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26       If you've ever had to do this...
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28           eval "require $module";
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30       to get around the bareword caveats on require(), this module is for
31       you.  It creates a universal require() class method that will work with
32       every Perl module and its secure.  So instead of doing some arcane
33       eval() work, you can do this:
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35           $module->require;
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37       It doesn't save you much typing, but it'll make a lot more sense to
38       someone who's not a ninth level Perl acolyte.
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Methods

41       require
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43         my $return_val = $module->require           or die $@;
44         my $return_val = $module->require($version) or die $@;
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46       This works exactly like Perl's require, except without the bareword
47       restriction, and it doesn't die.  Since require() is placed in the
48       UNIVERSAL namespace, it will work on any module.  You just have to use
49       UNIVERSAL::require somewhere in your code.
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51       Should the module require fail, or not be a high enough $version, it
52       will simply return false and not die.  The error will be in $@ as well
53       as $UNIVERSAL::require::ERROR.
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55           $module->require or die $@;
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57       use
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59           my $require_return = $module->use           or die $@;
60           my $require_return = $module->use(@imports) or die $@;
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62       Like "UNIVERSAL::require", this allows you to "use" a $module without
63       having to eval to work around the bareword requirement.  It returns the
64       same as require.
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66       Should either the require or the import fail it will return false.  The
67       error will be in $@.
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69       If possible, call this inside a BEGIN block to emulate a normal "use"
70       as closely as possible.
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72           BEGIN { $module->use }
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SECURITY NOTES

75       UNIVERSAL::require makes use of "eval STRING".  In previous versions of
76       UNIVERSAL::require it was discovered that one could craft a class name
77       which would result in code being executed.  This hole has been closed.
78       The only variables now exposed to "eval STRING" are the caller's
79       package, filename and line which are not tainted.
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81       UNIVERSAL::require is taint clean.
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COPYRIGHT

84       Copyright 2001, 2005 by Michael G Schwern <schwern@pobox.com>.
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86       This program is free software; you can redistribute it and/or modify it
87       under the same terms as Perl itself.
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89       See http://www.perl.com/perl/misc/Artistic.html
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AUTHOR

92       Michael G Schwern <schwern@pobox.com>
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94       Now maintained by Neil Bowers (NEILB).
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