【无标题】

就这样

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h> 

void dostuff(int); /* function prototype */

void error(const char *msg)
{
    perror(msg);
    exit(0);
}

int main(int argc, char *argv[])
{
    int sockfd, portno, n, newsockfd, pid, time;
    struct sockaddr_in serv_addr;
    struct hostent *server;

    char buffer[256], buffer2[256];
    if (argc < 3) {
       fprintf(stderr,"usage %s hostname port\n", argv[0]);
       exit(0);
    }
    portno = atoi(argv[2]);

    //create a socket
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) 
        error("ERROR opening socket");


    server = gethostbyname(argv[1]);
    if (server == NULL) {
        fprintf(stderr,"ERROR, no such host\n");
        exit(0);
    }
    bzero((char *) &serv_addr, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    bcopy((char *)server->h_addr, 
         (char *)&serv_addr.sin_addr.s_addr,
         server->h_length);
    serv_addr.sin_port = htons(portno);

    //connect
    if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0)
    {
        error("ERROR connecting");
    }
    printf("Connect success: ");

    bzero(buffer,256);
    bzero(buffer2,256);

    while(1)
    {
        n = read(sockfd, buffer, sizeof(buf));    //从客户端读数据
        if(n == -1)
        {
            printf("read failed\n");
            exit(1);
        }
        write(STDOUT_FILENO, buf, n);   //将数据打印到终端
    }
    close(sockfd);
     return 0; /* we never get here */
    // bzero(buffer,256);
    // fgets(buffer,255,stdin);
    //write and read data
    // n = write(sockfd,buffer,strlen(buffer));
    // if (n < 0) 
    //      error("ERROR writing to socket");
    // bzero(buffer,256);
    // bzero(buffer2,256);
    //n = read(sockfd,buffer,255);
    // if (n < 0) 
    //      error("ERROR reading from socket");
    // printf("%s\n",buffer);

//  while (1) {
//         bzero(buffer,256);
        
//          pid = fork();
//          if (pid < 0)
//              error("ERROR on fork");
//          if (pid == 0)  {
//              //close(sockfd);
//              dostuff(newsockfd);
//              exit(0);
//          }
//          else close(newsockfd);
//      } /* end of while */
//      close(sockfd);
//      return 0; /* we never get here */
// }

/******** DOSTUFF() *********************
 There is a separate instance of this function 
 for each connection.  It handles all communication
 once a connnection has been established.
 *****************************************/
    void dostuff (int sock)
    {
       int n;
       char buffer[256];
          
       bzero(buffer,256);
       n = read(sock,buffer,255);
       if (n < 0) error("ERROR reading from socket");
       printf("Here is the message: %s\n",buffer);
       n = write(sock,"I got your message",18);
       if (n < 0) error("ERROR writing to socket");
    }

}