PHP常用函数推荐

 
1.产生随机字符串函数
function random($length) {
 $hash = '';
 $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';
 $max = strlen($chars) - 1;
 mt_srand((double)microtime() * 1000000);
 for($i = 0; $i < $length; $i++) {
  $hash .= $chars[mt_rand(0, $max)];
 }
 return $hash;
}
2.截取一定长度的字符串
注：该函数对GB2312使用有效
function wordscut($string, $length ,$sss=0) {
 if(strlen($string) > $length) {
               if($sss){
                      $length=$length - 3;
                      $addstr=' ...';
                }
  for($i = 0; $i < $length; $i++) {
   if(ord($string[$i]) > 127) {
    $wordscut .= $string[$i].$string[$i + 1];
    $i++;
   } else {
    $wordscut .= $string[$i];
   }
  }
  return $wordscut.$addstr;
 }
 return $string;
}
3.取得客户端IP地址
function GetIP(){
             if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
                   $ip = getenv("HTTP_CLIENT_IP");
             else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
                &n