What contains a dru file?
All the settings that can be done in the Design Rules, for example, information about the Layer Setup, minimum distances, minimum wire width and drill diameters, permitted values for restrings of vias and pads, the shape of the pads, settings for solder stopmask and cream frame, and so on. In the dru directory, a subdirectory of the eagle directory, you will find a file named default.dru. It contains basic settings, EAGLE uses by default for new board files. In case you messed all the settings up, simply load this file to get usable default values. Design Rules will be stored in the board file directly. It’s not necessary to pass this file to your board house. Autorouter Control File – *.ctl This file can be created by the user. After adjusting the cost factors and parameters for the Autorouter in the Autorouter Setup Window (AUTO command) it is possible to save these settings in a ctl file, for example, for future routing jobs. In order to save a ctl file goto the General tab and clic
