


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


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



perl v5.10.1                2008-09-29                          1





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


       <nospam-abuse@bloodgate.com> 2007.

SEE ALSO
       perlsub, perlfunc.





















































perl v5.10.1                2008-09-29                          2


