How do you launch the PHP interactive shell?

October 26, 2018

As of PHP 5.1.0, the CLI SAPI provides an interactive shell. To use it, enter the following command at a command line:

<?php
php -a

If you run 'php -a' and just see 'Interactive mode enabled', but nothing happens when you type something and hit enter then this means that the interactive shell isn't activated for your installation of PHP. You must have the readline module installed (check if you do by running php -m | grep -i readline).

If you see 'Interactive mode enabled', then after typing in your PHP code (don't forget the opening PHP tag), press ctrl+d

$ php -a

Interactive mode enabled

<?php echo "hello, world" . rand(); ?>

hello, world665146942

Note: in the above output, I hit ctrl+d in the 2nd to last line, then it executed the PHP code that I typed and echoed the output.