Course of Raku / Functional, concurrent, reactive, and web programming / Web programming / A simple HTTP server / Exercises / Upper-case the path

Solution: Upper-case the path

Here is a possible solution to the task.

Code

my $listener = IO::Socket::INET.new(
    :listen,
    :localhost('127.0.0.1'),
    :localport(8080),
);

loop {
    my $conn = $listener.accept;
    my $request = $conn.recv;

    # "GET /hello HTTP/1.0" — the path is the second word; drop the leading '/'
    my $reply = $request.lines.first.words[1].substr(1).uc;

    $conn.print("HTTP/1.0 200 OK\r\nContent-Type: text/plain\r\n\r\n$reply\n");
    $conn.close;
}

🦋 You can find the source code in the file text-response.raku.

Output

HELLO

Comments

1. .recv reads the request. Its first line is GET /hello HTTP/1.0; .words[1] picks out /hello, and .substr(1) drops the leading slash to leave hello.

2. .uc upper-cases it, and that becomes the response body. The reply now depends on what the client asked for — the server is processing the request, not returning a fixed string.

3. The whole accept-read-respond block sits inside a loop, so the server answers one request after another instead of stopping after the first. Stop it with Ctrl-C.

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