Command Line Options - Undo

There are some classic things thing AutoCAD has pretty much always done, but they tend to get lost in time. They are usually linked to forgotten or never used command line options. Once a command is entered there are options to most of them that you can control at the command line. I'll post more in the future, but for now one of my favorite, most versatile, and under used command options goes to the UNDO command.

Auto: Groups the actions of a command, making them all reversible by a single undo.

All: Turns on the full UNDO command.

None: Turns off the U and UNDO commands and discards any UNDO command information saved earlier in the editing session.

One: Limits UNDO to a single operation.

Combine: Controls whether multiple, consecutive zoom and pan commands are combined as a single operation for undo and redo operations. Pan and zoom commands that are started from the menu are not combined, and always remain separate actions.

Layer: Controls whether the layer dialog operations are combined as a single undo operation.

Begin/End: This option groups actions together driven by the user. I use this in lisp.

Mark/Back: Mark places a book mark in the undo log. At a later time you can chose to undo back to the last Mark you placed in the log. If there are no marks, undo back will take you back to when you first opened the drawing. You will get an alert telling you so. I like this for the times I wished I nevere open a drawing in the first place.