Lesson 10	Setting and reading cookies
Objective	Learn how to set and read cookies.

Setting and Reading Cookies in Raku

In Raku (formerly known as Perl 6), cookie management is typically handled in the context of a web framework, like Cro, Bailador, or HTTP::Easy. However, even without a full framework, you can still read and set cookies in a web application or CGI script.
Here's how to set and read cookies in Raku:
✅ Setting Cookies in Raku (Perl 6)
You send cookies to the browser by writing them in the `Set-Cookie` HTTP header. 🔹 Example: Set a Cookie Manually

say "Set-Cookie: user=Thomas; Path=/; HttpOnly";
say "Content-Type: text/html\n";

say "<html><body>Cookie set!</body></html>";

> This must be part of your HTTP response header before sending content.
✅ Reading Cookies in Raku (Perl 6)
You can read incoming cookies from the `HTTP_COOKIE` environment variable.
🔹 Example: Read Cookies from the Request

my %cookies = $*ENV<HTTP_COOKIE>
    .split(';')
    .map({ .trim.split('=', 2) })
    .map({ $_[0] => $_[1] })
    .Hash;

say "Content-Type: text/plain\n";
say "User: " ~ (%cookies // 'No user cookie found');

✅ Example: Full CGI-style Raku Script

#!/usr/bin/env raku

# Set a cookie
say "Set-Cookie: user=Thomas; Path=/; HttpOnly";
say "Content-Type: text/html\n";

# Read cookies from incoming request
my %cookies = $*ENV<HTTP_COOKIE>
    .split(';')
    .map({ .trim.split('=', 2) })
    .map({ $_[0] => $_[1] })
    .Hash;

say "<html><body>";
say "User cookie: " ~ (%cookies<user> // 'none');
say "</html></body>";

✅ Using a Web Framework: Cro
If you are using Cro (a modern Raku web framework):
🔹 Set a Cookie

response(200, 'OK', [
    Set-Cookie => 'user=Thomas; Path=/'
], 'Cookie set!');

🔹 Read a Cookie

my $user = request.headers{'cookie'}.substr(/'user=' (.*?)(\;|\z)/)[0];

🧠 Summary

Task	Raku Code Snippet
Set Cookie	`say "Set-Cookie: key=value; Path=/; HttpOnly"`
Read Cookie	`my %cookies = $*ENV<HTTP_COOKIE>...`
Framework	Use Cro's `Set-Cookie` header and request header parsing

Legacy Perl Cookie Setting

To send a cookie from a CGI program, simply send the Set-cookie header sometime before the end of your headers, like this:

$crlf = "\x0d\x0a";        
$cookiehead = "UserID=007";  

print "content-type: text/html$crlf";
print "set-cookie: $cookiehead$crlf";
print "$crlf";
...rest of program

Reading a cookie To see what cookies are coming back from the client, check the $ENV{HTTP_COOKIE} variable like this:
```
$cookie = $ENV{HTTP_COOKIE};
print "<p>Here's a cookie: $cookie<br>\n" if $cookie;
```
It is valuable to keep in mind (especially when you are testing your code!) that you won't see the cookie come back from the browser until the next connection. It takes a whole round-trip (in other words, Connection A: send the cookie to the browser; Connection B: get the cookie from the browser) for the cookie to appear.

Set Perl Cookie - Quiz

Click the quiz link below for another exciting and challenging (and brief) multiple choice quiz on cookies.
Set Perl Cookie - Quiz