suse man page for core

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

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

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

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

SEE ALSO
       perlsub, perlfunc.

perl v5.12.1							    2010-04-26								 CORE(3pm)