=head1 NAME CORE - Pseudo-namespace for Perl's core routines =head1 SYNOPSIS BEGIN { *CORE::GLOBAL::hex = sub { 1; }; } print hex("0x50"),"\n"; # prints 1 print CORE::hex("0x50"),"\n"; # prints 80 =head1 DESCRIPTION The C namespace gives access to the original built-in functions of Perl. There is no C 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 L. =head1 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 C 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 C 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 C prefix: print CORE::hex("0x50"),"\n"; # prints 80 =head1 AUTHOR This documentation provided by Tels 2007. =head1 SEE ALSO L, L. =cut