function rand_str() {
$characters = '0123456789-=+{}[]:;@#~.?/>,<|!"£$%^&*()abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
$randomstr = '';
for ($i = 0; $i < random_int(50, 100); $i++) {
$randomstr .= $characters[rand(0, strlen($characters) - 1)];
}
return $randomstr;
}