Example of php file_get_content compatibility detection

<?php
/**
 * PHP 兼容性函数
 * http://bbs.it-home.org
 */
if(!function_exists('file_put_contents')) {
 if(!defined('FILE_APPEND')) define('FILE_APPEND', 8);
   function file_put_contents($filename, $data, $flag = 0) {
   $return = false;
   if($fp = @fopen($filename, $flag != FILE_APPEND ? 'w' : 'a')) {
      if($flag == LOCK_EX) @flock($fp, LOCK_EX);
         $return = fwrite($fp, is_array($data) ? implode('', $data) : $data);
         fclose($fp);
  }
  return $return;
 }
}
?>