Drush is the command line shell and Unix scripting interface for Drupal. The most common way to install Drush is to install it on a per-project basis using Composer. We'll walk through the steps to do that, as well as how to set up the Drush Launcher tool (to make it possible to execute Drush commands without having to specify a full path to the executable).

In this tutorial we'll:

• Install Drush
• Install Drush Launcher
• Verify it worked

By the end of this tutorial you'll have Drush installed.

Administration and maintenance of Drupal websites consists of many tasks that can both be performed via the command line, and automated, with Drush. Using Drush's site and environment administration commands you can run database updates, check an environment's status, clear (rebuild) the cache, perform Cron-related operations, and manage users. These tasks are repetitive, often require many steps in the UI, and may be tedious in the long run. Learning to execute them with Drush can save you time and allows for more automation of common tasks.

In this tutorial we'll:

One of the problems that Drush solves for developers is the automation and optimization of routine tasks. Drush commands attempt to speed up workflows and tasks that developers and site maintainers would otherwise have to do manually through the UI, or run one-by-one via the command line. One of those tasks is the process of deploying changes to a Drupal application from one environment to another.

While Drush empowers all Drupal users with its commands, it's even more powerful when used in combination with scripting solutions such as Composer and Bash. Scripts can be used to power post-deployment tasks like importing new configuration or clearing the cache, as part of CI processes to sync a database from one environment to another, to run background processes on the server such as imports and migrations, search indexing, running cron, and much more. If you want to write Bash (or any other scripts) that interact with a Drupal site, then Drush is the tool for you.

The Drush executable can be configured through the use of YAML configuration files and environment variables. This configuration can help cut down on typing lengthy frequently-used commands. You can tell Drush to look for command files in project-specific locations. Configuration can also set the value(s) of a specific command's options, instead of having to type them at the command line every time.

In this tutorial we'll:

Code generators are great productivity boosters that allow generating scaffolds for common development tasks in Drupal. One of the most common use cases for generators is scaffolding the code required for a custom entity type. Custom entities require many files and complicated annotations in order to function properly. There is a lot of boilerplate code that is more-or-less the same for every entity type. Creating all of the files is repetitive, time consuming, and prone to human error.

Developers can implement the Drush command API to write their own custom Drush commands. This allows you to include Drush commands with your modules to allow the module's features to be used via the CLI. You can also create project-specific Drush commands that help with the development, deployment, and maintenance of your particular application.

Make your custom Drush command more flexible by allowing users to pass command line arguments into it. For example, rather than hard-coding that the command lists users with a specific status, allow the desired status to be specified at run-time. This allows the command's logic to be more generic, and to return different results, or operate on different data, based on the provided parameters.

When the logic of a command depends on user input, it's useful to set up an interactive questionnaire inside the command code. This allows you to provide the user with more context about the input they're providing, and ensure that you collect all the necessary values. This is especially useful when the command uses a pre-defined list of options and the values require memorization. An example of this is the drush cache-clear command that comes with Drush core.

When you manage many Drupal websites, you may perform repetitive tasks that are common across all of your sites. In our experience, this usually relates to having a personal preference for how certain tasks are accomplished. For example: maybe you like to make backups of the database and files in a specific way before testing upgrades, or you have a set of scripts for running scans of core web vitals. Although these tasks can be bundled into a custom module, it could be useful to create a site-wide Drush command instead.

Often, there's an existing Drush command that does most of what you want, but needs just a few tweaks or enhancements to make it meet your project requirements. Maybe the existing core Drush command has the functionality but lacks some additional validation. Or maybe you need to add an additional option to perform some application-specific debugging logic for all commands in a group.

Drush hooks can be used to alter, extend, and enhance existing Drush commands.

In this tutorial we'll: