Saving Window Configurations in Registers
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You can save the window configuration of the selected frame in a
register, or even the configuration of all windows in all frames, and
restore the configuration later.
`C-x r w R'
Save the state of the selected frame's windows in register R
(`window-configuration-to-register').
`C-x r f R'
Save the state of all frames, including all their windows, in
register R (`frame-configuration-to-register').
Use `C-x r j R' to restore a window or frame configuration. This is
the same command used to restore a cursor position. When you restore a
frame configuration, any existing frames not included in the
configuration become invisible. If you wish to delete these frames
instead, use `C-u C-x r j R'.