php 判断是否存在恶意字符实例

function is_bad_chars($str){
 $bad_chars = array("",' ',"'",'"','/','*',',','<','>',"r","t","n",'$','(',')','%','+','?',';','^','#',':','　','`','=','|','-');
 foreach($bad_chars as $value){
  if (strpos($str,$value) !== false){
   return true;
  }
 }
}

function outip($ip){//排除ip
@$txt = file_get_contents("ip/ip.txt" );
$txtarr = explode("rn" , trim($txt));
 if(count($txtarr)<0){
  return false;
    }
   if(in_array($ip,$txtarr)){
  return true;
 }else{
  return false;
 }
}