task
Essentially, count the number of occurrences of =={{header| on each task page.

Output:

100 doors: 20 examples.
99 Bottles of Beer: 29 examples.
Abstract type: 10 examples.

Total: X examples.
For a full output, updated periodically, see Rosetta Code/Count examples/Full list.

You'll need to use the Media Wiki API, which you can find out about locally, here, or in Media Wiki's API documentation at, API:Query

use HTTP::Tiny;
 
my $site = "http://rosettacode.org";
my $list_url = "/mw/api.php?action=query&list=categorymembers&cmtitle=Category:Programming_Tasks&cmlimit=500&format=xml";
 
my $response = HTTP::Tiny->new->get("$site$list_url");
for ($response->{content} =~ /cm.*?title="(.*?)"/g) {
    (my $slug = $_) =~ tr/ /_/;
    my $response = HTTP::Tiny->new->get("$site/wiki/$slug");
    my $count = () = $response->{content} =~ /toclevel-1/g;
    print "$_: $count examples\n";
}