linux网络编程socket服务器端实现

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

#define buffersize 1024

int main()
{
//定义两个进程，一个是发送信息进程，一个是接收信息进程
pid_t caller;
pid_t recevier;

/* 建立socket连接 */

//保存socket信息
struct sockaddr_in client_sock;
struct sockaddr_in server_sock;

char buffer[buffersize];
int socketfd;

//开始建立,AF_UNSPEC不仅支持ipv4也支持ipv6
if ((socketfd = socket(AF_UNSPEC, SOCK_STREAM, 0)) == -1)
{
perror("Establish failed");
exit(1);
}

server_sock.sa_family= AF_UNSPEC;
server_sock.sin_port = htons(22);
server_sock.sin_addr.s_addr = INADDR_ANY;
bzero(&(server_sock.sin_zero), 8);

int i = 1;
setsocketopt(socketfd,SOL_SOCKET,SO_REUSEADDR,&i,sizeof(i));

//绑定socket`
if (bind(socketfd, (struct sockaddr_in *) &server_sock, sizeof(struct sockaddr_in)) == -1)
{
perror("Bind fail...");
exit(-1);
}

//监听
if (listen(socketfd,MAX_QUE_CONN_NM) == -1)
{
perror("Listen fail...");
exit(-1);
}
printf("listen....");

//如果有请求则接受
if (accept(socketfd, (struct sockaddr_in *)&client_sock, &sin_size) == -1)
{
perror("no accept...");
exit(-1);
}

//接收信息
if (recvfrom(socketfd, buffer, buffersize, 0) == -1)
{
perror("receive fail...");
exit(-1);
}
printf("receive information: %s",buffer);

//关闭连接
close(socketfd);
exit(0);

}