Client

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#include "conio.h"

#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "Mswsock.lib")
#pragma comment (lib, "AdvApi32.lib")

#define SERVER_IP_ADDRESS "127.0.0.1"
#define SERVER_PORT 27016
#define BUFFER_SIZE 256

// TCP client that use blocking sockets
int main()
{
    // Socket used to communicate with server
    SOCKET connectSocket = INVALID_SOCKET;

    // Variable used to store function return value
    int iResult;

    // Buffer we will use to store message
    char dataBuffer[BUFFER_SIZE];

	// WSADATA data structure that is to receive details of the Windows Sockets implementation
     WSADATA wsaData;

	// Initialize windows sockets library for this process
    if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0)
    {
        printf("WSAStartup failed with error: %d\n", WSAGetLastError());
        return 1;
    }

    // create a socket
    connectSocket = socket(AF_INET,
                           SOCK_STREAM,
                           IPPROTO_TCP);

    if (connectSocket == INVALID_SOCKET)
    {
        printf("socket failed with error: %ld\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    // Create and initialize address structure
    sockaddr_in serverAddress;
    serverAddress.sin_family = AF_INET;								// IPv4 protocol
	serverAddress.sin_addr.s_addr = inet_addr(SERVER_IP_ADDRESS);	// ip address of server
    serverAddress.sin_port = htons(SERVER_PORT);					// server port

    // Connect to server specified in serverAddress and socket connectSocket
    if (connect(connectSocket, (SOCKADDR*)&serverAddress, sizeof(serverAddress)) == SOCKET_ERROR)
    {
        printf("Unable to connect to server.\n");
        closesocket(connectSocket);
        WSACleanup();
		return 1;
    }

	// Read string from user into outgoing buffer
	printf("Enter message to send: ");
	gets_s(dataBuffer, BUFFER_SIZE);

    // Send message to server using connected socket
    iResult = send( connectSocket, dataBuffer, (int)strlen(dataBuffer), 0 );

	// Check result of send function
    if (iResult == SOCKET_ERROR)
    {
        printf("send failed with error: %d\n", WSAGetLastError());
        closesocket(connectSocket);
        WSACleanup();
        return 1;
    }

	printf("Message successfully sent. Total bytes: %ld\n", iResult);

	// Shutdown the connection since we're done
    iResult = shutdown(connectSocket, SD_BOTH);

	// Check if connection is succesfully shut down.
    if (iResult == SOCKET_ERROR)
    {
        printf("Shutdown failed with error: %d\n", WSAGetLastError());
        closesocket(connectSocket);
        WSACleanup();
        return 1;
    }

	// For demonstration purpose
	printf("\nPress any key to exit: ");
	getch();


    // Close connected socket
    closesocket(connectSocket);

	// Deinitialize WSA library
    WSACleanup();

    return 0;
}