16.3 Using Other Windows

C-x o

Select another window (other-window). That is the letter ‘o’, not zero.

M-C-v

Scroll the next window (scroll-other-window).

M-x compare-windows

Find the next place where the text in the selected window does not match the text in the next window.

M-x other-window-any-frame n

Select the nth different window on any frame.

To select a different window, use C-x o (other-window). That is an ‘o’, for ‘other’, not a zero. When there are more than two windows, the command moves through all the windows in a cyclic order, generally top to bottom and left to right. From the rightmost and bottommost window, it goes back to the one at the upper left corner. A numeric argument, n, moves several steps in the cyclic order of windows. A negative numeric argument moves around the cycle in the opposite order. If the optional second argument which-frames is non-nil, the function cycles through all frames. When the minibuffer is active, the minibuffer is the last window in the cycle; you can switch from the minibuffer window to one of the other windows, and later switch back and finish supplying the minibuffer argument that is requested. See Minibuffer Edit.

The command M-x other-window-any-frame also selects the window n steps away in the cyclic order. However, unlike other-window, this command selects a window on the next or previous frame instead of wrapping around to the top or bottom of the current frame, when there are no more windows.

The usual scrolling commands (see Display) apply to the selected window only. M-C-v (scroll-other-window) scrolls the window that C-x o would select. Like C-v, it takes positive and negative arguments.

The command M-x compare-windows compares the text in the current window with the text in the next window. Comparison starts at point in each window. Point moves forward in each window, a character at a time, until the next set of characters in the two windows are different. Then the command is finished.

A prefix argument ignore-whitespace means ignore changes in whitespace. The variable compare-windows-whitespace controls how whitespace is skipped.

If compare-ignore-case is non-nil, changes in case are also ignored.