Why is the variable sometimes empty?

Question

cmd/bat

Hello, please tell me, there is a script for autoit that checks every 30 seconds that the program is connected over the network, everything works fine, but sometimes at random time, it can be 5 minutes, or maybe several hours or several minutes, the $str variable turns out to be empty, as if the program is no longer connected over the network and the program is restarted, but in fact the program does not lose connection and continues to work, how can I fix such a bug and what could be the problem ?

Func timer()
   Sleep(30000) ; 30 sec
   qry()
EndFunc
Local $str = ''
    Local $pid = Run(@ComSpec & " /c " & 'netstat -a -n | findstr ":80"', '', @SW_HIDE, 2)
    While ProcessExists($pid)
        $str &= StdoutRead($pid)
    WEnd
    if $str Then
        _DebugOut (_NowTime() & ": Процесс активен")
    timer()
    Else
    _DebugOut (_NowTime() & ": Процесс не активен")
    Start()
    EndIf

Answer 1

Searching findstr ":80" in netstat means that it is looking for information that a certain program has opened a connection either from port 80 or port 80. And this can be a browser, and some running program, and even Windows auto-update. Some too general rule you got.
In addition, the connection of your program cannot be eternal, connections tend to be interrupted, for technical reasons. And it all depends on how quickly the program restores the connection, if it restores it at all. If the script hits a moment when the connection is not restored, then there will be an empty result. The simplest thing is to do a second check after, for example, 10 seconds, and if there is still no connection, then do a (re)start.