I found this code when looking for and example of doing an HTTP POST with only core modules. A snipette is below: 
  . . .
print $sock "POST https://$host/ HTTP/1.1\r\n";
print $sock "Connection: close", "\r\n";
print $sock "Host: ", $host, "\r\n";
print $sock "Content-length: ", length $req, "\r\n";
print $sock "Content-type: application/json\r\n";  #RFC 4627
print $sock $req, "\r\n\r\n";

print while <$sock>;   # << ???????

close $sock;

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It is always better to have seen your target for yourself, rather than depend upon someone else's description.

In reply to A curiosity by Wiggins

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