I know you requested no lectures, but the code you posted had some fundamental errors that make me wonder whether it is a good idea for you to be playing with fire. It's your business if you want to hang yourself, but I feel uneasy handing you the rope for it. I just had to get this off my chest. OK, end of sermonette.
I found at least three major errors in your code (more if all the code was intended to reside in a single file). The first one is that it's package, all lower case. What you wrote is equivalent to Foo->Package (see perlobj) . Next, it is not enough to use Exporter; you need to make your class a subclass of it. Like this:
or (my preferred idiom):package Foo; use Exporter; our @ISA = ( 'Exporter' );
(There are more idioms for doing this; see perlobj). The third thing is that the entries in @EXPORT, @EXPORT_OK, etc. are supposed to be strings. Something like @EXPORT_OK = ( &frobozz ) will put the value returned by the frobozz subroutine (whatever that is) in @EXPORT_OK, which, unless frobozz is the rare function that narcissistically returns its own name, won't do you any good.package Foo; use base 'Exporter';
OK, so here's what you do:
Note that the code in the example above is split over two files; it won't work as written if you put it all in one file.# file Foo.pm package Foo; use strict; use warnings; use Exporter; our @ISA = ( 'Exporter' ); our @EXPORT_OK = ( 'sysread' ); sub sysread { warn "this is not the real thing\n"; } 1; __END__ # file test.pl use strict; use warnings; package Bar; use Foo 'sysread'; warn "about to test sysread\n"; sysread; __END__ % perl test.pl about to test sysread this is not the real thing
Definitely give a very good read or two to the relevant section of perlsub that I cited before.
the lowliest monk
In reply to Re^3: using Exporter to overwrite a core function
by tlm
in thread using Exporter to overwrite a core function
by Forsaken
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