您可以通过UNIX域套接字将文件描述符传递给另一个进程。这是传递此类文件描述符的代码，摘自Unix
Network Programming
ssize_twrite_fd(int fd, void *ptr, size_t nbytes, int sendfd){ struct msghdr msg; struct iovec iov[1];#ifdef HAVE_MSGHDR_MSG_ConTROL union { struct cmsghdr cm; char control[CMSG_SPACe(sizeof(int))]; } control_un; struct cmsghdr *cmptr; msg.msg_control = control_un.control; msg.msg_controllen = sizeof(control_un.control); cmptr = CMSG_FIRSTHDR(&msg); cmptr->cmsg_len = CMSG_LEN(sizeof(int)); cmptr->cmsg_level = SOL_SOCKET; cmptr->cmsg_type = SCM_RIGHTS; *((int *) CMSG_DATA(cmptr)) = sendfd;#else msg.msg_accrights = (caddr_t) &sendfd; msg.msg_accrightslen = sizeof(int);#endif msg.msg_name = NULL; msg.msg_namelen = 0; iov[0].iov_base = ptr; iov[0].iov_len = nbytes; msg.msg_iov = iov; msg.msg_iovlen = 1; return(sendmsg(fd, &msg, 0));}这是接收文件描述符的代码
ssize_tread_fd(int fd, void *ptr, size_t nbytes, int *recvfd){ struct msghdr msg; struct iovec iov[1]; ssize_t n; int newfd;#ifdef HAVE_MSGHDR_MSG_ConTROL union { struct cmsghdr cm; char control[CMSG_SPACe(sizeof(int))]; } control_un; struct cmsghdr *cmptr; msg.msg_control = control_un.control; msg.msg_controllen = sizeof(control_un.control);#else msg.msg_accrights = (caddr_t) &newfd; msg.msg_accrightslen = sizeof(int);#endif msg.msg_name = NULL; msg.msg_namelen = 0; iov[0].iov_base = ptr; iov[0].iov_len = nbytes; msg.msg_iov = iov; msg.msg_iovlen = 1; if ( (n = recvmsg(fd, &msg, 0)) <= 0) return(n);#ifdef HAVE_MSGHDR_MSG_ConTROL if ( (cmptr = CMSG_FIRSTHDR(&msg)) != NULL && cmptr->cmsg_len == CMSG_LEN(sizeof(int))) { if (cmptr->cmsg_level != SOL_SOCKET) err_quit("control level != SOL_SOCKET"); if (cmptr->cmsg_type != SCM_RIGHTS) err_quit("control type != SCM_RIGHTS"); *recvfd = *((int *) CMSG_DATA(cmptr)); } else *recvfd = -1; #else if (msg.msg_accrightslen == sizeof(int)) *recvfd = newfd; else *recvfd = -1; #endif return(n);}
