[SOLVED] check that a intra net server listens to a TCP socket

[guest58172]

Under windows I have to wait until a local server starts to listen to a particular TCP port.
To do so:

Code: Pascal  [Select][+][-]

1. function checkSocket: boolean;
2. var
3.   prt: word = 9166;
4.   cli: TInetSocket = nil;
5. begin
6.   sleep(100); // because this proc is looped
7.   result := false;
8.   try try
9.     cli := TInetSocket.Create('localhost', prt);
10.   except
11.     // fail to connect error interpreted as "the server occupies the port"
12.     result := true;
13.   end;
14.   finally
15.     if assigned(cli) then
16.       cli.Free;
17.   end;
18. end;

It seems to work however once it returns true, the server fails to create its connection to the socket because it looks like my checker blocks the port.

What's the proper way to check if a port is available or not ?

[balazsszekely]

Run with TProcess "netstat -a" then parse the result.

[guest58172]

Yeah, this is what I gonna do. I'll wait a bit before considering this Q as solved to see if anyone has a solution using a socket, which would be cleaner.

[balazsszekely]

Maybe this helps:

Code: Pascal  [Select][+][-]

1. cli.SocketOptions:= cli.SocketOptions - [soKeepAlive];

Alternatively you could use the closesocket api(https://msdn.microsoft.com/en-us/library/windows/desktop/ms737582%28v=vs.85%29.aspx).