40.2 Basic Device Functions

Function: device-list

This function returns a list of all existing devices.

Function: device-or-frame-p object

This function returns non-nil if object is a device or frame. This function is useful because devices and frames are similar in many respects and many functions can operate on either one.

Function: device-frame-list &optional device

This function returns a list of all frames on device. device defaults to the currently selected device.

Function: frame-device &optional frame

This function returns the device that frame is on. frame defaults to the currently selected frame.