#

## undo

Undo commands

### Shortcuts:

> Key macro U implements the command undo.

### Usage:

> undo [print [count]]
> undo enable|disable

> > where count indicates a number of events to be undone (default 1 event), and must be a nonzero positive integer.

### Summary:

> The undo command reverses the effect of the last executed command (command-line, script, or macro-invoked), returning the layout to the state it was in prior to execution of that command.

> Certain commands in magic disable the undo mechanism, thus preventing the command from being undone. These include layout reads and writes, CIF, GDS, and LEF/DEF reads and writes.

> The print option generates a stack trace of the top count events in the undo stack, in excruciating detail.

> The undo disable option disables the command queue and prevents all following commands to be undoable until the undo enable command option is given. This can save time and memory for operations in a batch file where commands will never be able to be undone.

### Implementation Notes:

> undo is implemented as a built-in window command in magic.

### See Also:

> redo

Return to command index

Last updated: June 22, 2021 at 8:26pm