How can I install composer for php 5.2?

composer-php, php

Solution

You can't, because Composer requires PHP 5.3.2 or later:

System requirements

Composer requires PHP 5.3.2+ to run. A few sensitive php settings and compile flags are also required, but the installer will warn you about any incompatibilities.

To install packages from sources instead of simple zip archives, you will need git, svn or hg depending on how the package is version-controlled.

Composer is multi-platform and we strive to make it run equally well on Windows, Linux and OSX.

Problem

Original source