TCPserver.c

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

#define MY_PORT 8888

int main(int argc,char **argv) {
	int listen_fd,accept_fd;
	struct sockaddr_in client_addr;
	int n;

	if((listen_fd = socket(AF_INET,SOCK_STREAM,0)) < 0) {
		printf("Socket Error:%s\n\a",strerror(errno));
		exit(1);
	}
	bzero(&client_addr,sizeof(struct sockaddr_in));
	client_addr.sin_family = AF_INET;
	client_addr.sin_port = htons(MY_PORT);
	client_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	n = 1;
	// 如果服务器终止,服务器可以第二次快速启动
	setsockopt(listen_fd,SOL_SOCKET,SO_REUSEADDR,&n,sizeof(int));
	if(bind(listen_fd,(struct sockaddr *)&client_addr,
		sizeof(client_addr)) < 0) {
		printf("Bind Error:%s\n\a",strerror(errno));
		exit(1);
	}
	listen(listen_fd,5);
	while(1) {
		accept_fd = accept(listen_fd,NULL,NULL);
		if((accept_fd < 0) && (errno == EINTR))
			continue;
		else if(accept_fd < 0) {
			printf("Accept Error:%s\n\a",strerror(errno));
			continue;
		}
		if((n = fork()) == 0) {
			// 子进程处理客户端的连接
			char buffer[1024];
			close(listen_fd);
			n = read(accept_fd,buffer,1024);
			write(accept_fd,buffer,n);
			close(accept_fd);
			exit(0);
		} else if(n < 0)
			printf("Fork Error:%s\n\a",strerror(errno));
		close(accept_fd);
	}
}