[php] Execute php file from another php

It's trying to run it as a shell script, which interprets your <?php token as bash, which is a syntax error. Just use include() or one of its friends:

For example, in a.php put:

<?php
print "one";
include 'b.php';
print "three";
?>

In b.php put:

<?php
print "two";
?>

Prints:

eric@dev ~ $ php a.php
onetwothree