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authorSiep Kroonenberg <siepo@cybercomm.nl>2011-02-17 16:52:23 +0000
committerSiep Kroonenberg <siepo@cybercomm.nl>2011-02-17 16:52:23 +0000
commit8da2d23733595367fad869e5fbc6c9a87041879b (patch)
tree0f3719f4eea97f872b6347c6d9ff5aa2ccd38299 /Master/tlpkg/tlperl/lib/CORE.pod
parent9d55a4cf517a832c74e85179eac4239f9be8d2e7 (diff)
New tlperl part VIII
git-svn-id: svn://tug.org/texlive/trunk@21430 c570f23f-e606-0410-a88d-b1316a301751
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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
+
+=head1 DESCRIPTION
+
+The C<CORE> namespace gives access to the original built-in functions of
+Perl. 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