client.c

是在linux下的一个网络通行的简单程序 先运行server 再运行client

#include<stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#define SERVPORT 3333
#define MAXDATASIZE 100

main(int argc, char *argv[]){
 int sockfd, recvbytes; 
 char buf[MAXDATASIZE]; 
 struct hostent *host; 
 struct sockaddr_in serv_addr; 
 if (argc < 2) {
     fprintf(stderr,"Please enter the server's hostname!\n");
     exit(1);
    }
  if((host=gethostbyname(argv[1]))==NULL) { 
     herror("gethostbyname wrong!");
     exit(1);
    }
  if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1){  
     perror("socket creat wrong!");
     exit(1);
    }

   serv_addr.sin_family=AF_INET;  
   serv_addr.sin_port=htons(SERVPORT); 
   serv_addr.sin_addr = *((struct in_addr *)host->h_addr);
   //serv_addr.sin_addr = iner_addr(argv[1]);
 bzero( &(serv_addr.sin_zero),8);

 if (connect(sockfd, (struct sockaddr *) &serv_addr, 
 sizeof(struct sockaddr)) == -1) { 
perror("connect wrong!");
exit(1);
}
 if ((recvbytes=recv(sockfd, buf, MAXDATASIZE, 0)) ==-1) {
perror("recv wrong!");
exit(1);
}
 buf[recvbytes] = '\0'; 
 printf( "Received: %s",buf);
 close(sockfd);  
}