Script that installs composer and runs composer install (e.g. if you don't have console access to your server).

install.php

<?php

error_reporting(E_ERROR);
ini_set('display_errors', 1);

define('SOURCE_DIR', '..');
define('HOME_DIR', '/');
define('COMPOSER_HOME_DIR', HOME_DIR . 'composer/');
// define if you need access to a private repository on github
// define('OAUTH_TOKEN', '1234');

chdir(SOURCE_DIR);

if (is_readable('composer.json')) {

    $output = array();
    putenv('COMPOSER_HOME=' . COMPOSER_HOME_DIR);
    putenv('HOME=' . HOME_DIR);

    if (!is_readable(HOME_DIR.'composer.phar')) {
        chdir(HOME_DIR);
        copy('https://getcomposer.org/installer', 'composer-setup.php');
        if (hash_file('SHA384', 'composer-setup.php') === '92102166af5abdb03f49ce52a40591073a7b859a86e8ff13338cf7db58a19f7844fbc0bb79b2773bf30791e935dbd938') {
            echo 'Installer verified. Things look pretty good. Just as Xima. After finishing - call this script again to install vendors...</br></br>';
            // composer-setup.php will terminate request...
            require_once 'composer-setup.php';
        } else {
            unlink('composer-setup.php');
            exit ('Installer corrupt');
        }
    }

    if (is_readable(HOME_DIR.'composer-setup.php')) {
        unlink(HOME_DIR.'composer-setup.php');
    }

    if (defined('OAUTH_TOKEN')) {
        exec('php_cli ' . HOME_DIR . 'composer.phar config -g github-oauth.github.com ' . OAUTH_TOKEN, $output);
    }
    putenv('COMPOSER_DISCARD_CHANGES=true');

    $command = 'php_cli '.HOME_DIR.'composer.phar install';
    $output[] = '<i>'.$command.'...</i>';
    exec($command, $output);
    $output[] = '';

    $command = 'php_cli '.HOME_DIR.'composer.phar show';
    $output[] = '<i>'.$command.'...</i>';
    exec($command, $output);

    echo implode('<br/>'.PHP_EOL, $output);
    echo '<br/><br/>';

    // remove oauth token for security reasons every time
    if (defined('OAUTH_TOKEN')) {
        unlink(COMPOSER_HOME_DIR . 'auth.json');
    }
    echo 'Done.';

} else {
    echo 'No composer.json found.';
}