TCP_State

version 6.5

TCP_State (tcp_ID; statusCode) Integer

The TCP_State command returns an integer value corresponding to the state of a particular TCP connection.

tcp_ID is a long integer reference to an open TCP session as established with either the TCP_Open or TCP_Listen command.

statusCode is an integer variable returned which corresponds to one of the status codes below.

0	Connection Closed
2	Listening for an incoming connection
8	Established

This example assumes that a valid TCP connection has already been established and is identified by the Longint value assigned to the $tcp_id variable. In this example, a command is sent to a web server requesting a page of information and then a loop is entered to receive the results. Since web servers automatically close their connnections once they have performed their action, this example keeps receiving until the connection is dropped or an error occurs.

   C_LONGINT($tcp_id)
   C_INTEGER(vState;$err)
   C_TEXT($command;$buffer;$response)
   If (TCP_Send ($tcp_id;$command)=0)
      vState:=0
      Repeat
         $err:=TCP_Receive ($tcp_id;$buffer)
         $err:=TCP_State ($tcp_id;vState)
         $response:=$response+$buffer
      Until ((vState=0) | ($err#0))
   End if 

TCP_Listen, TCP_Open.