pid_t fork( void);返回值: 若成功调用一次则返回两个值,子进程返回0,父进程返回子进程ID;否则,出错返回-1
int socketpair(int d, int type, int protocol, int sv[2]);建立一对匿名的已经连接的套接字
int ret = socketpair( PF_UNIX, SOCK_STREAM, 0, sig_pipefd );
int socket(int domain, int type, int protocol);
int setsockopt(int sockfd, int level, int optname,const void *optval, socklen_t optlen);//SOL_SOCKET http://man.cx/setsockopt
address.sin_port = htons( port );
int bind(int sockfd, const struct sockaddr *addr,socklen_t addrlen);
int listen(int sockfd, int backlog);
原文:http://www.cnblogs.com/anjsxz/p/3710685.html