Defining and Installing Composer Dependencies in PHP

You want to use Composer. This allows you to install new packages, upgrade, and get information about your existing packages.

Install Composer:

To execute a command, type the command name as the first argument on the command line:

To install Composer, you download the installer file and send it to PHP. Composer uses PHP to ensure your system is set up as it requires, handle any configuration settings, and complete the installation process.

When it’s done, you have a file called composer. phar in the current directory.

Composer is a PHP script, so you can ask PHP to run it:

Or, run it directly by putting composer.phar in the same location as PHP:

If you have problems, make sure you have permission to write to that directory and that the file is executable:

Your copy of PHP may be in a different place. To find it, run:

With Composer up and running, pass it commands to execute. For example, to install a package:

For a list of all valid Composer commands, use list.

Composer has commands for both using and developing packages; as a result, there are some commands that you may not need.

The archive command, for example, creates a new package. If you only run other people’s packages, you can safely ignore this command.
See Table 27-1 for a list of frequently used commands.
Table 27-1. Common Composer commands