php pre-commit lint that doesn't break on deleted files

pre-commit

#!php
<?php
$files = array();
exec('git diff-index --cached --diff-filter=ACMRTUXB --name-only HEAD', $files );
$exitcode = 0;

// dont redirect stderr to stdin, we will get the errors twice, redirect it to dev/null
if ( PHP_OS == 'WINNT' )
  $redirect = ' 2> NUL';
else
  $redirect = ' 2> /dev/null';

foreach( $files as $file ) {
  
  if ( !preg_match('/\.php$/i', $file ) or !is_file( $file ) )
    continue;
  
  exec('php -l ' . escapeshellarg( $file ) . $redirect, $output, $return );
  
  if ( !$return ) // php -l gives a 0 error code if everything went well
    continue;
  
  $exitcode = 1; // abort the commit
  array_shift( $output ); // first line is always blank
  array_pop( $output ); // the last message is always "Errors parsing httpdocs/test.php"
  
  echo implode("\n", $output ), "\n"; // an extra newline for it to look good
  
}

exit( $exitcode );