+void
+ser_unix_nop_raw (struct serial *scb)
+{
+ return; /* Always in raw mode */
+}
+
+/* Wait for input on scb, with timeout seconds. Returns 0 on success,
+ otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */
+
+int
+ser_unix_wait_for (struct serial *scb, int timeout)
+{
+ while (1)
+ {
+ int numfds;
+ struct timeval tv;
+ fd_set readfds, exceptfds;
+
+ /* NOTE: Some OS's can scramble the READFDS when the select()
+ call fails (ex the kernel with Red Hat 5.2). Initialize all
+ arguments before each call. */
+
+ tv.tv_sec = timeout;
+ tv.tv_usec = 0;
+
+ FD_ZERO (&readfds);
+ FD_ZERO (&exceptfds);
+ FD_SET (scb->fd, &readfds);
+ FD_SET (scb->fd, &exceptfds);
+
+ if (timeout >= 0)
+ numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, &tv);
+ else
+ numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, 0);
+
+ if (numfds <= 0)
+ {
+ if (numfds == 0)
+ return SERIAL_TIMEOUT;
+ else if (errno == EINTR)
+ continue;
+ else
+ return SERIAL_ERROR; /* Got an error from select or poll */
+ }
+
+ return 0;
+ }
+}
+
+/* Read a character with user-specified timeout. TIMEOUT is number of seconds
+ to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns
+ char if successful. Returns -2 if timeout expired, EOF if line dropped
+ dead, or -3 for any other error (see errno in that case). */
+
+static int
+do_unix_readchar (struct serial *scb, int timeout)
+{
+ int status;
+ int delta;
+
+ /* We have to be able to keep the GUI alive here, so we break the original
+ timeout into steps of 1 second, running the "keep the GUI alive" hook
+ each time through the loop.
+
+ Also, timeout = 0 means to poll, so we just set the delta to 0, so we
+ will only go through the loop once. */
+
+ delta = (timeout == 0 ? 0 : 1);
+ while (1)
+ {
+
+ /* N.B. The UI may destroy our world (for instance by calling
+ remote_stop,) in which case we want to get out of here as
+ quickly as possible. It is not safe to touch scb, since
+ someone else might have freed it. The ui_loop_hook signals that
+ we should exit by returning 1. */
+
+ if (ui_loop_hook)
+ {
+ if (ui_loop_hook (0))
+ return SERIAL_TIMEOUT;
+ }
+
+ status = ser_unix_wait_for (scb, delta);
+ if (timeout > 0)
+ timeout -= delta;
+
+ /* If we got a character or an error back from wait_for, then we can
+ break from the loop before the timeout is completed. */
+
+ if (status != SERIAL_TIMEOUT)
+ {
+ break;
+ }
+
+ /* If we have exhausted the original timeout, then generate
+ a SERIAL_TIMEOUT, and pass it out of the loop. */
+
+ else if (timeout == 0)
+ {
+ status = SERIAL_TIMEOUT;
+ break;
+ }
+ }
+
+ if (status < 0)
+ return status;
+
+ while (1)
+ {
+ status = read (scb->fd, scb->buf, BUFSIZ);
+ if (status != -1 || errno != EINTR)
+ break;
+ }
+
+ if (status <= 0)
+ {
+ if (status == 0)
+ return SERIAL_TIMEOUT; /* 0 chars means timeout [may need to
+ distinguish between EOF & timeouts
+ someday] */
+ else
+ return SERIAL_ERROR; /* Got an error from read */
+ }
+
+ scb->bufcnt = status;
+ scb->bufcnt--;
+ scb->bufp = scb->buf;
+ return *scb->bufp++;
+}
+
+/* Perform operations common to both old and new readchar. */
+
+/* Return the next character from the input FIFO. If the FIFO is
+ empty, call the SERIAL specific routine to try and read in more
+ characters.
+
+ Initially data from the input FIFO is returned (fd_event()
+ pre-reads the input into that FIFO. Once that has been emptied,
+ further data is obtained by polling the input FD using the device
+ specific readchar() function. Note: reschedule() is called after
+ every read. This is because there is no guarentee that the lower
+ level fd_event() poll_event() code (which also calls reschedule())
+ will be called. */
+