gistfile1.php

#!/usr/bin/php
<?php

// A git pre-commit script for drupal-based repositories

$output = array();
$return = 0;
exec('git rev-parse --verify HEAD 2> /dev/null', $output, $return);
$against = $return == 0 ? 'HEAD' : '4b825dc642cb6eb9a060e54bf8d69288fbee4904';

exec("git diff-index --cached --name-only {$against}", $output);

$filename_pattern = '/\.(php|engine|theme|install|inc|module|test)$/';
$exit_status = 0;

foreach ($output as $file) {
  if (!preg_match($filename_pattern, $file) || !file_exists($file)) {
    // don't check files that aren't PHP
    continue;
  }

  $lint_output = array();
  exec("php -l " . escapeshellarg($file), $lint_output, $return);
  if ($return == 0) {
    continue;
  }
  echo implode("\n", $lint_output), "\n";
  $exit_status = 1;
}

exit($exit_status);