File content as of revision 0:4e0f31b64b24:

    

#include "mbed.h" //MbedOS 5.15
#include "EthernetInterface.h"
 
#define BUFFSIZE 50
 
#define PORT            80
 
DigitalOut led1(LED1);
 
EthernetInterface net;
TCPSocket server;
TCPSocket* client;
SocketAddress clientAddress;
 
char   *in_buffer;
char   *out_buffer;

static const char*          mbedIP       = "192.168.0.32";  //IP 
static const char*          mbedMask     = "255.255.255.0";  // Mask
static const char*          mbedGateway  = "192.168.0.0";    //Gateway

 
int main (void){
    printf("TCP Echo starting...\n");
    int net_stat;
//#ifndef ROUTER
    net.disconnect();
    net_stat = net.set_network(mbedIP,mbedMask,mbedGateway); //set ip, mask, gateway to net
    printf("set IP status: %i\n",net_stat);
//#endif
    net_stat = net.connect(); //connect to network
    printf("connect status: %i\n",net_stat);
 
    SocketAddress ip; //make socket for local ip address 
    net.get_ip_address(&ip); //get a info from net
    const char *p_ip = ip.get_ip_address();
    printf("IP address: %s and Port: %d\n", p_ip ? p_ip : "None" , PORT );
    SocketAddress mask;
    net.get_netmask(&mask);
    const char *p_mask = mask.get_ip_address();
    printf("Netmask: %s\n", p_mask ? p_mask : "None");
    SocketAddress gateway;
    net.get_gateway(&gateway);
    const char *p_gateway = gateway.get_ip_address();
    printf("Gateway: %s\n", p_gateway ? p_gateway : "None");
    
    if(ip){ 
        server.open(&net); //open a network socket using info of net
        server.bind(PORT); //bind the socket to a port which receive data
        server.listen(1); //prepare for incoming connections
        while (1) {
            
            printf("Server bound and listening\n");
            client = server.accept(); //wait until connection has done
            client->set_blocking(false);
            client->getpeername(&clientAddress);
            const char *p_clientAddress = clientAddress.get_ip_address();
            printf("Client connected from IP address: %s\n", p_clientAddress ? p_clientAddress : "None");
            
            bool b = true;
            while (b) {
                in_buffer = new char[BUFFSIZE];
                int n = client->recv(in_buffer, BUFFSIZE);
                
                printf("%d\n", n);
                
                if (n == 0) {
                    printf("Client disconnected\n");
                    b = false;
                }else if(n == NSAPI_ERROR_WOULD_BLOCK){
                    //printf("data is not here\n");
                }else{
                    in_buffer[n] = '\0';
                    printf("Received message from Client :'%s'\n", in_buffer);
                    out_buffer = new char[BUFFSIZE];
                    n = sprintf(out_buffer,"Echo - %s", in_buffer);
                    
                    printf("Sending echo to client\n");
                    //client->send(out_buffer, n);
                    led1 =! led1;
                    delete []out_buffer;
                }
                led1 =! led1;
                delete []in_buffer;
                wait_us(10000);
            }
            client->close();
        }
    }else{
            printf("No IP\n");
            net.disconnect();
            printf("Program end\n");
    }
}