- The UDP protocol
- Operating mode of UDP sockets
In french: SocketCréeUDP
Creates a socket that is using the UDP protocol.
IF SocketCreateUDP("Serveur", 8000) = False THEN
Error("Erreur création " + ErrorInfo(errMessage))
<Result> = SocketCreateUDP(<Socket name> , <Port number> [, <Address>])
- True if the function was successful,
- False otherwise. If an error occurs, you can get the details of the error with ErrorInfo.
<Socket name>: Character string
Name that will be given to the socket. This name will be used by all socket functions.
Caution: the socket name is case sensitive.
<Port number>: entier
Port number that will be given to the socket. This number must be included between 5000 and 65000. This number will be specified when the client computers are connected to the server.
<Address>: Optional character string
IP address on which the socket must be created on the current computer. If the current computer is associated with several IP addresses (or with several network cards), this parameter enables you to choose the IP address that will be associated with the socket.
This IP address can have the following format:
- IP address in XXX.XXX.XXX.XXX format (184.108.40.206 for example).
- IP address containing the name of the server (www.windev.com for example). This syntax is recommended.
- IP address returned by NetIPAddress.
The UDP protocol
When using UDP sockets, there is no notion of connection (as opposed to TCP sockets that are connection-oriented). UDP is a connectionless protocol.
All the UDP sockets, no matter whether they are client sockets or server sockets, are created by SocketCreateUDP.
When a write operation is performed via the UDP protocol, you must specify the destination (address and port).
When a read operation is performed via the UDP protocol, the origin of the string read is unknown. It is returned by SocketClientInfo
Remark: The UDP protocol is a connectionless protocol, there is no guarantee that the information sent was received.
Operating mode of UDP sockets
A port already opened by another application can be re-opened. The port will be closed during the call to SocketClose
or when ending the application that opened it.
You must be "root" to create a socket on a port less than or equal to 1024 (being "root" means being the user who has all the permissions on the system).
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