Software Collections make running more than one version of php on the same server pretty painless. It does take some getting use to.

PHP has lots of command line tools which assume that php is available in the environment; which isn’t the case in an SCL environment.

Assumptions

• Your using RedHat or CentOS 7.
• php 7.2 is installed via software collections. (rh-php72)
• PHP Composer’s “composer.phar” is downloaded in “/opt/php-composer/”

Here is a little bash script to work around this quirk of using SCL packages.

#! /bin/bash

#choose which scl package we want to use.
source scl_source enable rh-php72

#pass all shell args to composer.
php /opt/php-composer/composer.phar "$@"

Save this as “composer” and make it executable (chmod +x composer) and moved it into the “/usr/local/bin/” folder.

This trick also works for cron jobs which need a specific version of php to run.