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   1  =head1 NAME
   2  
   3  CORE - Pseudo-namespace for Perl's core routines
   4  
   5  =head1 SYNOPSIS
   6  
   7      BEGIN {
   8          *CORE::GLOBAL::hex = sub { 1; };
   9      }
  10  
  11      print hex("0x50"),"\n";            # prints 1
  12      print CORE::hex("0x50"),"\n";        # prints 80
  13  
  14  =head1 DESCRIPTION
  15  
  16  The C<CORE> namespace gives access to the original built-in functions of
  17  Perl. There is no C<CORE> package, and therefore you do not need to use or
  18  require an hypothetical "CORE" module prior to accessing routines in this
  19  namespace.
  20  
  21  A list of the built-in functions in Perl can be found in L<perlfunc>.
  22  
  23  =head1 OVERRIDING CORE FUNCTIONS
  24  
  25  To override a Perl built-in routine with your own version, you need to
  26  import it at compile-time. This can be conveniently achieved with the
  27  C<subs> pragma. This will affect only the package in which you've imported
  28  the said subroutine:
  29  
  30      use subs 'chdir';
  31      sub chdir { ... }
  32      chdir $somewhere;
  33  
  34  To override a built-in globally (that is, in all namespaces), you need to
  35  import your function into the C<CORE::GLOBAL> pseudo-namespace at compile
  36  time:
  37  
  38      BEGIN {
  39          *CORE::GLOBAL::hex = sub {
  40              # ... your code here
  41          };
  42      }
  43  
  44  The new routine will be called whenever a built-in function is called
  45  without a qualifying package:
  46  
  47      print hex("0x50"),"\n";            # prints 1
  48  
  49  In both cases, if you want access to the original, unaltered routine, use
  50  the C<CORE::> prefix:
  51  
  52      print CORE::hex("0x50"),"\n";        # prints 80
  53  
  54  =head1 AUTHOR
  55  
  56  This documentation provided by Tels <nospam-abuse@bloodgate.com> 2007.
  57  
  58  =head1 SEE ALSO
  59  
  60  L<perlsub>, L<perlfunc>.
  61  
  62  =cut