client1.c

使用winsock库中socket套间实现TCP/IP固定连接的程序,工程是完整的,只要在VC环境下重新编译一下就可以了.

/* Client1.c for Windows Developers Journal by Victor R. Volkman
 * this code may be used freely with no restrictions on use
 *
 * To build Win32 client   cl client1.c scompat.c /Z7 /MT 
 * To build Unix client    cc client1.c scompat.c -o client1
 */

#include <stdio.h>
#include "scompat.h"

/* try to tell linker where WinSock library is */
#if defined(_MSC_VER)
#   pragma comment(lib,"wsock32.lib")
#elif defined(__BORLANDC__)
#   pragma comment(lib,"mswsock.lib")
#endif


#define WSA_ERROR(x)  { printf("Error %d: %s\n", \
    WSAGetLastError(), x); return 1; }
void InitSockets(void);


main(int argc, char **argv)
{
    SOCKET sd_client;
    int err;
    u_short iPort;
    struct sockaddr_in addr_srv;
    struct hostent *ptrHost;
    char response[4096];
    char *pszHost;
    char *msg = "HELLO SERVER";

    if (argc == 3) {
      pszHost = argv[1];
      iPort = atoi(argv[2]);
      }
    else {
      printf("Usage:\t client1 [hostname] [portno]");
      return 1;
      }

    InitSockets();
    sd_client = socket(PF_INET, SOCK_STREAM, 0);
    if (sd_client == INVALID_SOCKET)
        WSA_ERROR("no more socket resources")

    if (atoi(pszHost)) {
        u_long ip_addr = inet_addr(pszHost);
        ptrHost = gethostbyaddr((char *)&ip_addr,
            sizeof(u_long), AF_INET);
        }
    else
        ptrHost = gethostbyname(pszHost);

    if (!ptrHost)
        WSA_ERROR("cannot resolve hostname")

    addr_srv.sin_family = PF_INET;
    memcpy((char *) &(addr_srv.sin_addr),
        ptrHost->h_addr,  ptrHost->h_length);
    addr_srv.sin_port = htons(iPort);

    err = connect(sd_client, (struct sockaddr *) &addr_srv,
        sizeof(addr_srv));
    if (err == INVALID_SOCKET)
        WSA_ERROR("cannot connect to server")

    printf("You are connected to the server\n");
    send (sd_client, msg, strlen(msg)+1, 0);
    memset(response, 0, sizeof(response));
    recv(sd_client, response, sizeof(response), 0);
    printf("server says %s\n", response);
    closesocket(sd_client);
    WSACleanup();
    return 0;
}