1. #include <pthread.h>
    2. #include <signal.h>
    3. #include "net.h"
    5. void cli_data_handle (void *arg);
    7. void sig_child_handle(int signo)
    8. {
    9.     if(SIGCHLD == signo) {
    10.         waitpid(-1, NULL,  WNOHANG);
    11.     }
    12. }
    13. int main (void)
    14. {
    16.     int fd = -1;
    18.     signal(SIGCHLD, sig_child_handle);    
    20.     /* 1. 创建socket fd */
    21.     if ((fd = socket (AF_LOCAL, SOCK_STREAM, 0)) < 0) { //基于本地的TCP通信
    22.         perror ("socket");
    23.         exit (1);
    24.     }
    26.     /* 允许绑定地址快速重用 */
    27.     int b_reuse = 1;
    28.     setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &b_reuse, sizeof (int));
    30.     /* 2.1 填充sockaddr_un结构体变量 */
    31.     struct sockaddr_un sun;
    32.     bzero(&sun, sizeof(sun));
    33.     sun.sun_family = AF_LOCAL;
    35.     /* 如果UNIX_DOMAIN_FILE所指向的文件存在，则删除 */
    36.     if(!access(UNIX_DOMAIN_FILE, F_OK)) {
    37.         unlink(UNIX_DOMAIN_FILE);
    38.     }
    39.     strncpy(sun.sun_path, UNIX_DOMAIN_FILE, strlen( UNIX_DOMAIN_FILE));
    42.     /*2.2 绑定 */
    43.     if (bind (fd, (struct sockaddr *) &sun, sizeof (sun)) < 0) {
    44.         perror ("bind");
    45.         exit (1);
    46.     }
    48.     /*3. 调用listen()把主动套接字变成被动套接字 */
    49.     if (listen (fd, BACKLOG) < 0) {
    50.         perror ("listen");
    51.         exit (1);
    52.     }
    53.     printf ("Unix domain server starting....OK!\n");
    54.     int newfd = -1;
    55.     /*4. 阻塞等待客户端连接请求 */
    56.     while(1) {
    57.         pid_t pid = -1;
    58.         if ((newfd = accept (fd, NULL,NULL)) < 0) {
    59.                         perror ("accept");
    60.                         break;
    61.                 }
    62.         /*创建一个子进程用于处理已建立连接的客户的交互数据*/
    63.         if((pid = fork()) < 0) {
    64.             perror("fork");
    65.             break;
    66.         }
    68.         if(0 == pid) {  //子进程中
    69.             close(fd);
    71.                         printf ("Clinet is connected!\n");    
    72.             cli_data_handle(&newfd);        
    73.             return 0;    
    75.         } else { //实际上此处 pid >0, 父进程中 
    76.             close(newfd);
    77.         }
    80.     }        
    83.     close (fd);
    84.     return 0;
    85. }
    87. void cli_data_handle (void *arg)
    88. {
    89.     int newfd = *(int *) arg;
    91.     printf ("Child handling process: newfd =%d\n", newfd);
    93.     //..和newfd进行数据读写
    96.     int ret = -1;
    97.     char buf[BUFSIZ];
    98.     char resp_buf[BUFSIZ+10];
    99.     while (1) {
    100.         bzero (buf, BUFSIZ);
    101.         do {
    102.             ret = read (newfd, buf, BUFSIZ - 1);
    103.         } while (ret < 0 && EINTR == errno);
    104.         if (ret < 0) {
    106.             perror ("read");
    107.             exit (1);
    108.         }
    109.         if (!ret) {                //对方已经关闭
    110.             break;
    111.         }
    112.         printf ("Receive data: %s\n", buf);
    114.         if (!strncasecmp (buf, QUIT_STR, strlen (QUIT_STR))) {    //用户输入了quit字符
    115.             printf ("Client(fd=%d) is exiting!\n", newfd);
    116.             break;
    117.         }
    119.         bzero(resp_buf, BUFSIZ+10);
    121.         strncpy(resp_buf, SERV_RESP_STR, strlen(SERV_RESP_STR));
    122.         strcat(resp_buf, buf);     
    123.         do {
    124.             ret = write(newfd, resp_buf, strlen(resp_buf));    
    125.         }while(ret < 0 && EINTR == errno);
    127.     }
    128.     close (newfd);
    130. }