Linux下Socket TCP的简单例子

#include<sys/socket.h>
#include <unistd.h>// for close function
#include <string.h> // for bzero function
#include<stdio.h>
#include<sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include<netinet/in.h>
#include <stdlib.h>
#define SERV_PORT 5555
#define SERV_IP "xxx.xxx.xxx.xxx"//mx27 board ip
#define BACKLOG 10 //the counts of connect can keep in wait queen
#define MAXBUFSIZE 200
char buf[MAXBUFSIZE]; //receive buf
char str_to_send[200] ="important notice:to cerebrate China log on moon successful on 12nd,Jan,2010. everyone has a day free from work!\n";
int main(int argc, char **argv)
{
 int sockfd,sockfd_client;
 socklen_t sin_size; // used in accept(),but i don't know what it means
 printf("#####################################################\n");
 printf("socket receive text        by pafone  30th,April,2009\n");
 printf("server ip:%s port:%d         \n",SERV_IP,SERV_PORT);
 printf("#####################################################\n");
 struct sockaddr_in my_addr;//local ip info
 struct sockaddr_in serv_addr,client_sockaddr; //server ip info
 int serverport;
 if(argc == 2)
 {
  serverport = atoi(argv[1]);
 }
 else
 {
  serverport = SERV_PORT;
 }
 if(-1 == (sockfd = socket(AF_INET,SOCK_STREAM,0)) )
 {
  perror("error in create socket\n");
  exit(0);
 }
 //set the sockaddr_in struct
 serv_addr.sin_family = AF_INET;
 serv_addr.sin_port = htons(serverport);//server listening port
 serv_addr.sin_addr.s_addr = INADDR_ANY;//here is the specia in listening tcp connect
 bzero(&serv_addr.sin_zero,8);
//bind , the ip and port information is aready in the sockaddr
 if(-1 == bind(sockfd,(struct sockaddr*)&serv_addr,sizeof(struct sockaddr)))
 {
  perror("bind error\n");
  exit(0);
 }
 printf("bind seccessful\n");
 
 if(-1 == listen(sockfd,BACKLOG))
 {
  perror("lisenning");
  exit(1);
 }
 printf("the server is listenning...\n");
 //accept
 printf("before accept:sockfd_client is %d\n",sockfd_client);
 if(-1 == (sockfd_client = accept(sockfd,(struct sockaddr*)&client_sockaddr,&sin_size)))
 {
  perror("accept");
  exit(1);
 }
 printf("accept connect.\n");
 int recvbytes;//the number of bytes receive from socket
// char buffer[200];
// printf("sockfd_client is %d\n",sockfd_client);
// recvbytes = recv(sockfd_client,buffer,200,0);
 if(-1 == (recvbytes = recv(sockfd_client,buf,MAXBUFSIZE,0)))//changed here
 if(-1 == recvbytes)
 {
  perror("receive");
  exit(1);
 }
 printf("%dbytes receive from connect:%s\n",recvbytes,buf);
 close(sockfd);
 close(sockfd_client);
}