example71.c

LinuxNetProgramming Linux网络编程基础实例

/* example71.c */
#include	<sys/types.h>
#include	<sys/socket.h>
#include	<netinet/in.h>
#include	<stdio.h>
#define		MAXLEN	1024
#define		SERV_PORT	8080
#define		BACKLOG		5

void serv();
int
main()
{
	int		listenfd, connetfd;
	pid_t		childpid;
	socklen_t	clilen;
	struct sockaddr_in cliaddr, servaddr;
	if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
		perror("socket error");
		exit(0);
	}
	bzero(&servaddr, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
	servaddr.sin_port = htons(SERV_PORT);
	if ((bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr))) < 0) {
		perror("bind error");
		exit(0);
	}
	if (listen(listenfd, BACKLOG) < 0) {
		perror("listen error");
		exit(0);
	}
	for ( ; ; ) {
		clilen = sizeof(cliaddr);
		connetfd = accept(listenfd, (struct sockaddr *)&cliaddr, &clilen);
		if ((childpid = fork()) == 0) {
			close(listenfd);
			serv(connetfd);
			exit(0);
		}
		close(connetfd);
	}
}
void
serv(int connfd)
{
	ssize_t	n;
	char	line[MAXLEN];
	for ( ; ; ) {
		if ((n = read(connfd, line, MAXLEN)) == 0) {
			perror("connect closed by client");
			exit(0);
		}
		if (line[0] == '1') {
			sleep(3);
			write(connfd, "server respons to client1", 26);
		}
		else
			write(connfd, "server respons to client2", 26);
	}
}