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recvfrom

recvfrom(socket::UDPSocket) -> (address, data)

Read a UDP packet from the specified socket, returning a tuple of (address, data), where address will be either IPv4 or IPv6 as appropriate.

Examples

1. Receive UDP packet and extract address and data:

   julia> sock = UDPSocket();
   julia> bind(sock, "127.0.0.1", 12345);
   julia> (address, data) = recvfrom(sock);
   julia> address
   "127.0.0.1"
   julia> data
   "Hello, World!"

   In this example, we create a UDP socket, bind it to a specific address and port, and then use recvfrom to receive a UDP packet. The function returns a tuple containing the address from which the packet was received and the packet data.

2. Receive UDP packet and ignore address:

   julia> sock = UDPSocket();
   julia> bind(sock, "0.0.0.0", 12345);
   julia> (_, data) = recvfrom(sock);
   julia> data
   "Hello, World!"

   In this example, we use the underscore _ to ignore the address returned by recvfrom and only store the packet data.

3. Handle multiple UDP packets:

   julia> sock = UDPSocket();
   julia> bind(sock, "0.0.0.0", 12345);
   julia> for _ in 1:5
          (address, data) = recvfrom(sock);
          println("Received packet from $address: $data")
      end

   This example demonstrates receiving multiple UDP packets in a loop. Each time recvfrom is called, it blocks until a packet is received. The address and data are then printed.

Common mistake example:

julia> sock = UDPSocket();
julia> (address, data) = recvfrom(sock);
ERROR: UndefVarError: UDPSocket not defined

In this example, the UDPSocket type is not defined because the Sockets module has not been imported. Make sure to import the necessary modules before using the functions they provide.

See Also

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