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VIDEO_ON_OFF(9r)
NAME
  VIDEO_ON_OFF - Graphics: Turns the video on or off on a specific screen

SYNOPSIS
  #include sys/ioctl.h
  #include sys/workstation.h

  int ioctl(
	  int gfx_fd,
	  unsigned long VIDEO_ON_OFF,
	  void *ws_driver_structure_pointer );

ARGUMENTS
  gfx_fd
      Specifies the file descriptor of the graphics device-special file (by
      convention /dev/ws0) that the open system call returns when the server
      is initialized. The server uses this file descriptor in subsequent
      ioctl calls to the Workstation Subsystem.

  VIDEO_ON_OFF
      Specifies the ioctl command used to access the ws_video_control
      structure.

  ws_driver_structure_pointer
      Specifies a pointer to the ws_video_control structure.

DESCRIPTION
  The VIDEO_ON_OFF ioctl command turns the video on or off. The screen is
  described by the ws_video_control structure defined in
  /usr/sys/include/sys/workstation.h and pointed to by
  ws_driver_structure_pointer.	Primarily, a screen saver uses this ioctl
  command, which is called from the WS layer of the Compaq device-dependent X
  (DDX) implementation. However, if you want to use some other method of
  blanking the screen (for example, to implement Green Mode or Deep Green
  Mode), then you would call this ioctl command from your board-specific DDX.

RESTRICTIONS
  The graphics subsystem supports only one workstation per machine.

RETURN VALUES
  If successful, the VIDEO_ON_OFF ioctl command returns 0 (zero). If
  unsuccessful, it returns -1.






EXAMPLE
  The following example shows how the generic WS layer of the DDX uses the
  VIDEO_ON_OFF ioctl command:

       Bool
       wsSaveScreen(pScreen, on)
	   ScreenPtr pScreen;
	   int on;
       {
	   ws_video_control vc;
	   vc.screen = WS_SCREEN(pScreen);
	   if (on == SCREEN_SAVER_FORCER) {
	       lastEventTime = queue->time;
	   } else if (on == SCREEN_SAVER_ON) {
	       vc.control = 0;
	       if (ioctl(wsFd, VIDEO_ON_OFF, &vc) < 0)
		   ErrorF("VIDEO_ON_OFF: failed to turn screen off.\n");
	   } else {
	       vc.control = 1;
	       if (ioctl(wsFd, VIDEO_ON_OFF, &vc) < 0)
		   ErrorF("VIDEO_ON_OFF: failed to turn screen on.\n");
	   }
	   return TRUE;
       }

FILES
  /usr/sys/include/sys/ioctl.h

  /usr/sys/include/sys/workstation.h

SEE ALSO
  ioctl Commands: CURSOR_ON_OFF(9r), GET_DEPTH_INFO(9r),
  MAP_SCREEN_AT_DEPTH(9r), SET_CURSOR_POSITION(9r)

Index for Section 9

Alphabetical listing for V

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