如何阻止搜索查询少于3

I'm making a search function for my website, but I want to block searches that are less then 3 characters

if($search > 3){
    header('Location: error.txt');
}

its probably something very simple. please help

You need to use strlen() to get the characters count.

 if(strlen($search) < 3){
   header('Location: error.txt');
}