git pre-commit hook that clean each modified file using php-cs-fixer

pre-commit

#!/usr/bin/php
<?php
exec('git diff --cached --name-status --diff-filter=ACM', $output);
foreach ($output as $file) {
    $fileName = trim(substr($file, 1) );
    if ("php" == pathinfo($fileName, PATHINFO_EXTENSION)) {
        $lint_output = array();
        exec("php -l " . escapeshellarg($fileName), $lint_output, $return);

        if ($return == 0) {
          exec("php-cs-fixer fix {$fileName} --config-file=.php_cs; git add {$fileName}");
                    echo $file.PHP_EOL;
        } else {
           echo implode("\n", $lint_output), "\n";
           exit(1);
        }
    }
}
echo 'All source-code is clean'.PHP_EOL;
exit(0);