Composer – quick start guide on Linux and Mac

Composer is a tool for dependency management in PHP. It allows you to declare the libraries your project depends on and it will manage (install/update) them for you.

Here is steps to install and getting started with composer on Linux and Mac.

1. Get composer phar (php archive)

   $ curl -sS https://getcomposer.org/installer | php
   $ ls -l 
   total 3080
   -rwxr-xr-x  1 user1  staff  1576802 Mar  4 00:12 composer.phar
   

2. List filenames in phar archive

   $ phar list -f composer.phar
   

   In case you want to browse files packed in conpose.phar, you can use phar extrat to extract all files in current dir. You may want to create a temporary directory before doing it.

   $ mkdir extracted; cd extracted
   $ phar list -f ../composer.phar
   $ ls -p
   LICENSE		bin/		res/		src/		vendor/
   

3. Install composer globally (optional). You can always run composer from local copy using php composer.phar. But it is convenient to install it globally in /usr/local/bin

   ## You may need sudo if /usr/local/bin is not writable by user
   $ mv composer.phar /usr/local/bin/composer
   

4. Assuming /usr/local/bin is in your PATH, you can run the following to print composer version.

   $ composer --version
   Composer version 1.0-dev (f2d606ae0c705907d8bfa1c6f884bced1255b827) 2016-03-03 12:44:49
   

5. Now we’ll create a project config file containing dependencies.
   Create composer.json in desired project dir (say my_composer_project) file with the following content. Alternatively you can also use composer init to create initial composer.json.

   {
       "require": {
           "monolog/monolog": "*"
       }
   }
   

6. Install packages using composer as per composer.json and create composer.lock. Note that re-running install will then read composer.lock and install stuff based on that. So if composer.json is modified, you need to run update.

   $ composer install
   $ ls 
   composer.json	composer.lock	vendor
   $ ls vendor/monolog/monolog/
   CHANGELOG.mdown		README.mdown		doc			src
   LICENSE			composer.json		phpunit.xml.dist	tests
   

   Note: Composer will display a Warning when executing an install command if composer.lock and composer.json are not synchronized

7. To run composer update (in case composer.json is changed). This will update composer.lock based on composer.json.

   $ composer update
   

8. To add required package (say mockery) to your composer.json and install it

   $ composer require mockery/mockery
   $ cat composer.json 
   {
       "require": {
           "monolog/monolog": "*",
           "mockery/mockery": "^0.9.4"
       }
   }
   

9. List info about installed packages

   $ composer info
   monolog/monolog 1.18.0 Sends your logs to files, sockets, inboxes, databases and various web services
   psr/log         1.0.0  Common interface for logging libraries