From QB64 Wiki
The _CONNECTIONADDRESS function returns a connected user's STRING IP address value.
- result$ = _CONNECTIONADDRESS[$](connectionHandle&)
- The handle can come from the _OPENHOST, OPENCLIENT or _OPENCONNECTION QB64 TCP/IP functions.
- For HOSTs: It may return "TCP/IP:8080:126.96.36.199" where 8080 is the port it is listening on and 188.8.131.52 is the global IP address which any computer connected to the internet could use to locate your computer. If a connection to the internet is unavailable or your firewall blocks it, it returns your 'local IP' address (127.0.0.1). You might like to store this address somewhere where other computers can find it and connect to your host. Dynamic IPs which can change will need to be updated.
- For CLIENTs: It may return "TCP/IP:8080:184.108.40.206" where 8080 is the port it used to connect to the listening host and 220.127.116.11 is the IP address of the host name it resolved.
- For CONNECTIONs (from clients): It may return "TCP/IP:8080:34.232.321.25" where 8080 was the host listening port it connected to and 34.232.321.25 is the IP address of the client that connected. This is very useful because the host can log the IP address of clients for future reference (or banning, for example).
- The $ sygil is optional for compatibility with older versions.
Example: A Host logging new chat clients in a Chat program. See the _OPENHOST example for the rest of the code used.
f = FREEFILE OPEN "ChatLog.dat" FOR APPEND AS #f ' code at start of host section before DO loop. newclient = _OPENCONNECTION(host) ' receive any new client connection handles IF newclient THEN numclients = numclients + 1 ' increment index Users(numclients) = newclient ' place handle into array IP$ = _CONNECTIONADDRESS(newclient) PRINT IP$ + " has joined." ' displayed to Host only PRINT #f, IP$, numclients ' print info to a log file PRINT #Users(numclients),"Welcome!" ' from Host to new clients only END IF
- Explanation: The function returns the new client's IP address to the IP$ variable. Prints the IP and the original login position to a log file. The information can later be used by the host for referance if necessary. The host could set up a ban list too.