cli.c

socket 发送接收字符串

//file name : cli.c

#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 PORT 3999 
#define MAXDATASIZE 100 /*max data volume */ 

main(int argc, char *argv[])
{ 
 int sockfd, numbytes; 
 char buf[MAXDATASIZE]; 
 struct hostent *he; 
 struct sockaddr_in their_addr; 
 if (argc != 2)
 { 
  fprintf(stderr,"Please enter the server's hostname!\n"); 
  exit(1); 
 } 
 if((he=gethostbyname(argv[1]))==NULL)
 { 
  herror("gethostbyname error"); 
  exit(1); 
 } 
 if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
 { 
  perror("socket create error"); 
  exit(1); 
 } 
 their_addr.sin_family = AF_INET; 
 their_addr.sin_port = htons(PORT); 
 their_addr.sin_addr = *((struct in_addr *)he->h_addr); 
 bzero(&(their_addr.sin_zero),8); 
 if (connect(sockfd, (struct sockaddr *)&their_addr, sizeof(struct sockaddr)) == -1)
 { 
  perror("connect error"); 
  exit(1); 
 } 
 if (( numbytes = recv(sockfd, buf, MAXDATASIZE, 0)) == -1)
 { 
  perror("recv error"); 
  exit(1); 
 } 
 buf[numbytes] = '\0'; 
 printf("Received: %s",buf); 
 close(sockfd); 
}