How To

Making a WP-CLI Plugin

Messing around with wp-cli, it was fun to learn how to make a plugin … without a plugin.

I love wp-cli. It makes my life so much easier in so many ways.

I’ve added in some basic commands to some of my plugins because it makes things easier for others. And as it happens, adding wp-cli commands to your plugins isn’t actually all that hard. But did you know you don’t have to?

The Basic Code The Basic Code

For our example I’m going to make a command called halfelf and it’s going to have a sub-command called ‘stats’ which outputs that the HalfElf is alive. And that looks like this:

WP_CLI::add_command( 'halfelf', 'HalfElf_CLI' );

class HalfElf_CLI extends WP_CLI_Command {

	 * Get HalfElf Stats
	 * wp halfelf stats
	public function stats( ) {
		WP_CLI::success( __( 'HalfElf is currently alive.', 'halfelf' ) );

The docblock controls the output for the help screen, which is possibly the most brilliant thing about it.

Of course, all that does is make a command that doesn’t rely on any WordPress plugin, which is cool. Here’s a different example. In this one, I’m triggering a command to my logger function to reset the backup log or to view it:

	 * See Log Output
	 * ## OPTIONS
	 * empty: Leave it empty to output the log
	 * reset: Reset the log
	 * wp dreamobjects logs
	 * wp dreamobjects logs reset

	public function log( $args, $assoc_args  ) {
		if ( isset( $args[0] ) && 'reset' !== $args[0] ) {
			WP_CLI::error( sprintf( __( '%s is not a valid command.', 'dreamobjects' ), $args[0] ) );
		} elseif ( 'reset' == $args[0] ) {
			WP_CLI::success( 'Backup log reset' );
		} else {
			file_get_contents( './log.txt' );

Because wp-cli runs as WordPress, it has access to WordPress commands and functions.

But. Where do we put this file?

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In a WordPress Plugin In a WordPress Plugin

If you want to use that code in a WordPress plugin, you put it in a file called wp-cli.php (or whatever you want) and then call it in your main WordPress plugin file like this:

if ( defined( 'WP_CLI' ) && WP_CLI ) {
	require_once( 'wp-cli.php' );

If you do that, I would recommend putting this at the top of your wp-cli.php file.

if (!defined('ABSPATH')) {

// Bail if WP-CLI is not present
if ( !defined( 'WP_CLI' ) ) return;

That will prevent people from calling the file directly or in other ways.

In the case of my DHDO code, I added in this check:

if( class_exists( 'DHDO' ) ) {
	WP_CLI::add_command( 'dreamobjects', 'DreamObjects_Command' );

That means if (for whatever reason) DHDO can’t be found, it prevents you from doing things.

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On It’s Own On It’s Own

But. That first command doesn’t need a plugin, does it? So if it doesn’t need a plugin, could I still use them? The answer is of course. The wp-cli.php file is the same, but where you put it changes. This will all be done in SSH. You could do it in SFTP if you wanted.

In your home (or root) directory we have to make a folder called .wp-cli – please note the period, it’s like your .htaccess file. Except it’s a folder. In there you’re going to make a folder called commands and in that folder we’ll put another one for our commands. Like if I’m putting my HalfElf commands out there, I’d make a folder called halfelf and in there I put my command file command.php

That gives me this: ~/.wp-cli/commands/halfelf/command.php

However that doesn’t act like plugins or themes or mu-plugins, you have to add the command to another file. I know, I know. Make a file called config.yml and put it in .wp-cli so you have this: ~/.wp-cli/config.yml

The content of that file is this:

  - commands/halfelf/command.php
  - commands/some-other/command.php

And that’s it! Now you’ve got some command line tools for your WordPress site!

2 replies on “Making a WP-CLI Plugin”

Hi Does accessing wp-cli functions via a plugin mean that wp-cli still has to be installed in your server? or does WP actually already have wp-cli installed?

I am asking because I am on shared hosting and my hosting company does not allow access to the command line e.g. SSH to a command shell

I use wp-cli all the time when I am developing WP sites on my local machine but once I ‘publish’ my site to my host I don’t have the ability to use wp-cli any more e.g. to do maintenance on my site

I live in hope that its possible to access wp-cli functions via a plug in and that wp-cli is available in a WP install 🙂

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