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=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
CORE::say "yes"; # prints yes
=head1 DESCRIPTION
The C<CORE> namespace gives access to the original built-in functions of
Perl. It also provides access to keywords normally available
only through the L<feature> pragma. There is no C<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 L<perlfunc>.
=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<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 C<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 C<CORE::> prefix:
print CORE::hex("0x50"),"\n"; # prints 80
=head1 AUTHOR
This documentation provided by Tels <nospam-abuse@bloodgate.com> 2007.
=head1 SEE ALSO
L<perlsub>, L<perlfunc>.
=cut
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