PHP - function - add_escape_before_single_quote($str)

function add_escape_before_single_quote($str){
    //$str = "Sha'ash'wato";
    $str_len = strlen($str);
    $str_temp = "";
    for($c = 0; $c < $str_len; $c++){
        if($str[$c] == "'"){
            $str_temp .= "\'";
        }else{
            $str_temp = $str_temp.$str[$c];
        }
    }
    // echo $str_temp;
    return $str_temp;
}