"Undefined subroutine &HTML::Entities::decode_entities called"

Question

I'm getting the error

Undefined subroutine &HTML::Entities::decode_entities called`

using LWP::UserAgent, although the module is there, as well as the HTML::Parser module.

I suspect it has something to do with XS modules missing, since the function in question seems to be implemented in XS, but I am at a loss.

Answer 1

Are you missing this line:

use HTML::Entities;

From the HTML::Entities CPAN page, it should be used like this:

use HTML::Entities;
my $a = "Våre norske tegn bør &#230res";
decode_entities($a);
encode_entities($a, "\200-\377");

If you think there is something wrong with the HTML::Entities package, you can check the source on your system. From bash:

vim $(perldoc -l HTML::Entities)

Once the file is opened in your text editor, you can check that the subroutine is defined. I suspect that the package is correct though, it is more likely that the package isn't "used".

You can also test this at the command line to see if it works outside your program:

perl -MHTML::Entities -le 'print HTML::Entities::decode_entities( "Våre norske tegn bør &#230res" )'

Answer 2

Recent versions of HTML::Entities depend on getting the decode_entities routine by loading the HTML::Parser module's XS component. Since the two modules are distributed together, this should not be a problem, but it's possible you have an older HTML::Parser version that didn't use XS instead (or multiple versions of HTML::Parser installed, with the wrong one being found first).

Check the $VERSION in HTML::Parser, look up that distribution on http://search.cpan.org/dist/HTML-Parser, and verify that distribution has the version of HTML::Entities that you have.