检测服务器端口是否被占用

 1 for (int port=begin; port <= end; port++){
 2         /*定义socket*/
 3         int server_sockfd = socket(AF_INET, SOCK_STREAM, 0);
 4 
 5         /*定义sockaddr_in 的变量*/
 6         struct sockaddr_in server_sockaddr;
 7         server_sockaddr.sin_family = AF_INET;
 8         server_sockaddr.sin_addr.s_addr=htonl(INADDR_ANY);
 9         server_sockaddr.sin_port = htons(port);
10         //server_sockaddr.sin_port = 0; /*端口范围是0～65535 1~1023为保留端口号*/
11        
12         /*检查端口占用情况，列出占用端口号*/
13         if (bind (server_sockfd, (struct sockaddr *) &server_sockaddr, sizeof(
14         server_sockaddr)) == -1){
15             printf ("%d
", port);
16             alread_port_cnt++;
17             //break;
18         } else {
20             idle_port_cnt++;
21         }
22         close (server_sockfd);
23     }/*循环结束*/

用bind()函数就可以，成功返回0, 占用返回-1.

种树最好的时间是十年前，其次是现在。