回复 tcp socket通信例子

回复 http://www.oschina.net/code/snippet_102078_2670  tcp socket通信例子

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <errno.h>
#include <error.h>

#include <string.h>
#include <stdio.h>

#include <locale.h>

#define socket_error(status, name) if (status == -1) { \
	printf("ERROR: %d\n",errno); \
	error(-1, errno, "%s", name); \
}

int main(int argc, char **argv)
{
	int  status  = 0; 

	int                server;       
	struct sockaddr_in server_addr;  

	int                client;
	struct sockaddr_in client_addr;
	socklen_t          client_addr_len = sizeof(client_addr);

	/* fdsets */
	fd_set all_fds;
	fd_set read_fds;
	int    fd_max   = 0;
	int    fd_cur   = 0;
	int    fd_count = 0;


	setlocale(LC_ALL, "zh_CN.UTF-8");

	server = socket(PF_INET, SOCK_STREAM, 0); 
	socket_error(status, "server");

	/* 允许重新使用地址 */
	int reuseaddr = 1;
	status = setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &reuseaddr, sizeof(reuseaddr));
	socket_error(status, "setsockopt so_reuseaddr");

	server_addr.sin_family      = AF_INET; 
	server_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); 
	server_addr.sin_port        = htons(9090); 

	status = bind(server, (struct sockaddr*)&server_addr, sizeof(server_addr));
	socket_error(status, "bind");

	status = listen(server, 50);
	socket_error(status, "listen");

	/* 初使化all_fdsfds */
	FD_ZERO(&all_fds);

	/* 加入server到all_fds */
	FD_SET(server, &all_fds);

	/* 当前最大的描述符均为server */
	fd_max = server;
	while (1) {
		read_fds = all_fds;
		fd_count = select(fd_max+1, &read_fds, NULL, NULL, NULL);
		socket_error(fd_count, "select");

		int i=0;
		for (i=0; i < fd_max+1; ++i) {
			fd_cur = i;

			/* fd_cur没有处于read状态则跳过 */
			if (!FD_ISSET(fd_cur, &read_fds))
				continue;

			if (fd_cur == server ) {
				client = accept(server, (struct sockaddr*)&client_addr, &client_addr_len);
				socket_error(client, "accept");

				printf("%s connected\n", inet_ntoa(client_addr.sin_addr));

				/* 加入client到all_fds */
				FD_SET(client, &all_fds);
				if (client>fd_max)
					fd_max = client;

			} else {
				/* 客户端为fd_cur */
				client = fd_cur;

				/* Socket 相关操作 */

				/* 从all_fds中删除client并关闭client */
				FD_CLR(client, &all_fds);
				close(client);
			} 
		}

	}
	return 0;
}

转载于:https://my.oschina.net/jiangmiao/blog/11717