"php -l" before commit

pre-commit

#!/usr/bin/env php
<?php

$files = array();
$returnValue = 0;
$exitStatus = 0;
$acceptedExtensions = array('php');

# git revision
exec('git rev-parse --verify HEAD 2> /dev/null', $files, $returnValue);
$compare = ($returnValue == 0) ? 'HEAD' : '';

# changed files
exec("git diff-index --cached --name-only {$compare}", $files);

foreach($files as $file) {
  if (!file_exists($file) || is_dir($file)) {
    continue;
  }

  $ext = pathinfo($file, PATHINFO_EXTENSION);
  if (!in_array($ext, $acceptedExtensions)) {
    continue;
  }
  
  echo "Check {$file}...";

  $file = escapeshellarg($file);
  $dir = str_replace('\'', '', dirname($file));
  $extra = '';
  if ($dir !== '.') {
    $extra = $dir . '/';
  }

  $lintCmd = "php -l {$file}";
  $pipes = array();
  $descriptorspec = array(
    0 => array("pipe", "r"),  // stdin
    1 => array("pipe", "w"),  // stdout
    2 => array("pipe", "w"),  // stderr
  );

  $process = proc_open($lintCmd, $descriptorspec, $pipes);
  $stdout = stream_get_contents($pipes[1]);
  $stderr = stream_get_contents($pipes[2]);

  if (strlen($stderr) < 1) {
    echo "ok", PHP_EOL;
    continue;
  }
  echo "failed", PHP_EOL;
  if (preg_match('/on line ([0-9]+)/', $stderr, $matches)) {
    $exitStatus = 1;
    if (isset($matches[1])) {
      $output = "";
      $before = max($matches[1] - 2, 0);
      $after = $matches[1] + 2;
      exec("cat -n {$file} | sed -n {$before},${after}p", $output, $returnValue);
      echo "--- FAILED -----------", PHP_EOL;
      echo implode(PHP_EOL, $output), PHP_EOL;
      echo "----------------------", PHP_EOL;
    } else {
      echo $stderr;
    }
  }
}

if ($exitStatus > 0) {
  echo PHP_EOL, "PHP errors detected... Fix it before commit";
}

exit($exitStatus);