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CORE(3pm)                             Perl Programmers Reference Guide                             CORE(3pm)



NAME
       CORE - Pseudo-namespace for Perl's core routines

SYNOPSIS
           BEGIN {
               *CORE::GLOBAL::hex = sub { 1; };
           }

           print hex("0x50"),"\n";                     # prints 1
           print CORE::hex("0x50"),"\n";               # prints 80

DESCRIPTION
       The "CORE" namespace gives access to the original built-in functions of Perl. There is no "CORE"
       package, and therefore you do not need to use or require an hypothetical "CORE" module prior to
       accessing routines in this namespace.

       A list of the built-in functions in Perl can be found in perlfunc.

OVERRIDING CORE FUNCTIONS
       To override a Perl built-in routine with your own version, you need to import it at compile-time.
       This can be conveniently achieved with the "subs" pragma. This will affect only the package in which
       you've imported the said subroutine:

           use subs 'chdir';
           sub chdir { ... }
           chdir $somewhere;

       To override a built-in globally (that is, in all namespaces), you need to import your function into
       the "CORE::GLOBAL" pseudo-namespace at compile time:

           BEGIN {
               *CORE::GLOBAL::hex = sub {
                   # ... your code here
               };
           }

       The new routine will be called whenever a built-in function is called without a qualifying package:

           print hex("0x50"),"\n";                     # prints 1

       In both cases, if you want access to the original, unaltered routine, use the "CORE::" prefix:

           print CORE::hex("0x50"),"\n";               # prints 80

AUTHOR
       This documentation provided by Tels <nospam-abuse@bloodgate.com> 2007.

SEE ALSO
       perlsub, perlfunc.



perl v5.12.5                                     2012-11-03                                        CORE(3pm)