Fl_Connect is a working attempt to implement sockets in FLTK. Fl_Connect is currently working for windows but a linux version should be easy to do following the #ifdef WIN32 .

class Fl_Connect{

        #ifdef WIN32
        //for sending
        SOCKADDR_IN addr_Dest;
        SOCKET sock_Main;//use for listening too
        
        //for listening
        SOCKADDR_IN addr_Srv, addr_Cli;
        SOCKET sock_Listen;

        #endif
        
        
        char IP[20];
        short port;

public:
        bool connect(char inIP[20],short inPort);
        bool connectDNS(char *inDNS,short inPort);//TODO
        bool listen(int inPort);
        bool send(char* inBuffer,int inSizeOfBuffer);
        char *receive(int inLenghtOfMessage);
        bool close();
        

        Fl_Connect();
        ~Fl_Connect(){};

};