client.c

linux下套接字源码

#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 /*每次最大数据传输量 */ 
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出错！"); 
exit(1); 
} 
　if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1){ 
perror("socket创建出错！"); 
exit(1); 
} 
　serv_addr.sin_family=AF_INET; 
　serv_addr.sin_port=htons(SERVPORT); 
　serv_addr.sin_addr = *((struct in_addr *)host->h_addr); 
　bzero(&(serv_addr.sin_zero),8); 
　if (connect(sockfd, (struct sockaddr *)&serv_addr, \ 
　　 sizeof(struct sockaddr)) == -1) { 
perror("connect出错！"); 
exit(1); 
} 
　if ((recvbytes=recv(sockfd, buf, MAXDATASIZE, 0)) ==-1) { 
perror("recv出错！"); 
exit(1); 
} 
　buf[recvbytes] = '\0'; 
　printf("Received: %s",buf); 
　close(sockfd); 
}