I heard PM uses a simple regexp to identify code blocks and there's evidence* to support that. I don't know what the actual code is for displaytype=selectcode , displaytype=displaycode and displaytype=displaycode;part=X, but that same simple regexp would extract the code blocks quite easily. For example, the third page I mentioned could be generated with something as simple as 
my $post_body = ...from db...;
my $part = $cgi->param{part};
my $block = ($post_body =~ m{<c>(.*?)</c>}gi)[$part];

if (!defined($block)) {
   ...error...
} else {
   print("Content-Type: text/plain\n\n$block");
}

[download]

* — PM recognizes <c>...</c> but not <c >...</c> like it does for other tags, and PM recognizes code blocks inside of HTML comments.

In reply to Re: perlmonks downloadable code blocks by ikegami
in thread perlmonks downloadable code blocks by debiandude

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
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