Detecting offline computers in the LAN

[Mingre]

Hello again,

More than a week ago, I made this thread [Resolved] How to put ping() or similar alternative function a timeout asking for a faster alternative for the ping function. The last post states that I found a code good enough for what I want to achieve.

_list()

Func _list()
Local $foo, $sActiveLine, $line

$foo = Run(@ComSpec & " /c net view ", @SystemDir, @SW_HIDE, 2)

While 1
$sActiveLine = StdoutRead($foo)

If @error Then ExitLoop
If StringLeft($sActiveLine, 2) = "\\" Then
$line &= StringReplace($sActiveLine, "\\", "") & @CRLF
EndIf
WEnd

$line = StringReplace($line, " ", "")
$line = StringReplace($line, @LF, "")
$line = StringSplit($line, @CR)

TCPStartup()

For $i = 1 To $line[0] - 1
$result = Ping($line[$i], 1)
If Not @error Then
ConsoleWrite('>ONLINE : ' & $line[$i] & @CRLF)
Else
ConsoleWrite('+OFFLINE : ' & $line[$i] & @CRLF)
EndIf
Next
EndFunc ;==>_list

Earlier I also made this thread [sOLVED] stdoutread() question which includes the modification of the code. From how I phrased the function, the code presumably lists the turned-on computers in the local network. But only the first time.

Code as fixed by guinness

#include

ConsoleWrite(ListOnline() & @CRLF)

Func ListOnline()
Local $iPID = Run(@ComSpec & " /c net view ", @SystemDir, @SW_HIDE, $STDOUT_CHILD)
Local $sActiveLine = "", $sLines = ""
While 1
$sActiveLine = StdoutRead($iPID)
If @error Then ExitLoop
$sLines &= $sActiveLine
WEnd
Return $sLines
EndFunc ;==>ListOnline

The problem begins after I shutdown a computer in the local network. It still shows the turned-off computers. Perhaps you noticed that the mod was simply removing the ping function (because it's too laggy).

As for displaying the already turned-off computers, I know the problem isn't with AutoIt but with Windows XP's net view. While I was searching, I found this: http://www.pcreview.co.uk/forums/net-view-doesnt-refresh-often-t3671801.html. Like what the user said, the Microsoft's ping takes a long time to load when it's used for turned-off computers. I even tried making use of MS' ping timeout but the shortest time it can get is about 2000ms. (And if am not mistaken, it takes a little longer with AutoIt's ping, ~4000ms?)

I also had tried using cunningt's _PingLikeMicrosoft() as suggested by Robjong but it still takes around 2000ms.

So my questions are:

1. Is there a workaround to my problem, i.e., detecting which among the computers displayed by net view are actually turned-off?

2. Is there a way to clear net view cache using AutoIt so I could just re-run net view instead of pinging every displayed computer?

Thank you!

[BrewManNH]

I think you're going to have to compromise between speed and functionality. With networking, you usually can't have both working well, one is going to suffer if you want the other.

There are a LOT of network scanners out there and they all suffer from the same thing, they take a long time to populate the list, if you're doing it dynamically. If you do a once in a while update of the list, then speed isn't an issue, but if you want real-time, you're probably not going to be able to achieve it.