MSDN中的C／S代码实例－－Socket

增进测试初学者对代码的理解，这里我添加了客户端从文本读字符的功能：
有兴趣的可以添加自己想要的功能看看，比如，实现多线程等等。


Server:
// Server.cpp : Defines the entry point for the console application.
#include "stdafx.h"
#include <stdio.h>
#include "winsock2.h"
#pragma comment(lib, "WS2_32.LIB")


void main() {
    // Initialize Winsock.
    WSADATA wsaData;
    int iResult = WSAStartup( MAKEWORD(2,2), &wsaData );
    if ( iResult != NO_ERROR )
        printf("Error at WSAStartup()\n");
    // Create a socket.
    SOCKET m_socket;
    m_socket = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
    if ( m_socket == INVALID_SOCKET ) {
        printf( "Error at socket(): %ld\n", WSAGetLastError() );
        WSACleanup();
        return;
    }
    // Bind the socket.
    sockaddr_in service;
    service.sin_family = AF_INET;
    service.sin_addr.s_addr = inet_addr( "127.0.0.1" );
    service.sin_port = htons( 27015 );
    if ( bind( m_socket, (SOCKADDR*) &service, sizeof(service) ) == SOCKET_ERROR ) {
        printf( "bind() failed.\n" );
        closesocket(m_socket);
        return;
    }
   
    // Listen on the socket.
    if ( listen( m_socket, 1 ) == SOCKET_ERROR )
        printf( "Error listening on socket.\n");
    // Accept connections.
    SOCKET AcceptSocket;
    printf( "Waiting for a client to connect...\n" );
    while (1) {
        AcceptSocket = SOCKET_ERROR;
        while ( AcceptSocket == SOCKET_ERROR ) {
            AcceptSocket = accept( m_socket, NULL, NULL );
        }
        printf( "Client Connected.\n");
        m_socket = AcceptSocket;
        break;
    }
   
    // Send and receive data.
    int bytesSent;
    int bytesRecv = SOCKET_ERROR;
    char sendbuf[32] = "Server: Sending Data.";
    char recvbuf[32] = "";
   
    bytesRecv = recv( m_socket, recvbuf, 32, 0 );
    printf( "Bytes Recv: %ld\n", bytesRecv );
   
    bytesSent = send( m_socket, sendbuf, strlen(sendbuf), 0 );
    printf( "Bytes Sent: %ld\n", bytesSent );
    return;
}
 
Client:
 
// client.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <stdio.h>
#include "winsock2.h"
#pragma comment(lib, "WS2_32.LIB")
#include <stdlib.h>

void main() {
    // Initialize Winsock.
    WSADATA wsaData;
    int iResult = WSAStartup( MAKEWORD(2,2), &wsaData );
    if ( iResult != NO_ERROR )
        printf("Error at WSAStartup()\n");
    // Create a socket.
    SOCKET m_socket;
    m_socket = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
    if ( m_socket == INVALID_SOCKET ) {
        printf( "Error at socket(): %ld\n", WSAGetLastError() );
        WSACleanup();
        return;
    }
    // Connect to a server.
    sockaddr_in clientService;
    clientService.sin_family = AF_INET;
    clientService.sin_addr.s_addr = inet_addr( "127.0.0.1" );
    clientService.sin_port = htons( 27015 );
    if ( connect( m_socket, (SOCKADDR*) &clientService, sizeof(clientService) ) == SOCKET_ERROR) {
        printf( "Failed to connect.\n" );
        WSACleanup();
        return;
    }
    // Send and receive data.
    int bytesSent;
    int bytesRecv = SOCKET_ERROR;
    char sendbuf[32] = "";
    char recvbuf[32] = "";
 

 
 FILE *stream;
 int RNumber;
 if( (stream = fopen( "test.txt", "r" )) == NULL ) // C4996
  // Note: _wfopen is deprecated; consider using _wfopen_s instead
  {
   printf("fopen failed!\n");
   return;
  }
    if( ( RNumber = fread( sendbuf, sizeof( char ), 25, stream )) == 0)
 {
  printf("fread 0 character!\n");
  return;
 }
   
 bytesSent = send( m_socket, sendbuf, strlen(sendbuf), 0 );
    printf( "Bytes Sent: %ld\n", bytesSent );
    while( bytesRecv == SOCKET_ERROR ) {
        bytesRecv = recv( m_socket, recvbuf, 32, 0 );
        if ( bytesRecv == 0 || bytesRecv == WSAECONNRESET ) {
            printf( "Connection Closed.\n");
            break;
        }
        if (bytesRecv < 0)
            return;
  printf("Recv chartaacter:%s\n", recvbuf );
        printf( "Bytes Recv: %ld\n", bytesRecv );
    }
    return;
}