9.2 Editing in the Minibuffer

The minibuffer is an Emacs buffer (albeit a peculiar one), and the usual Emacs commands are available for editing the argument text.

Since <RET> in the minibuffer is defined to exit the minibuffer, you can't use it to insert a newline in the minibuffer. To do that, type C-o or C-q C-j. (The newline character is really the ASCII character control-J.)

The minibuffer has its own window, which normally has space in the frame at all times, but it only acts like an Emacs window when the minibuffer is active. When active, this window is much like any other Emacs window; for instance, you can switch to another window (with C-x o), edit text there, then return to the minibuffer window to finish the argument. You can even kill text in another window, return to the minibuffer window, and then yank the text into the argument. See section Multiple Windows.

There are some restrictions on the minibuffer window, however: you cannot kill it, or split it, or switch buffers in it—the minibuffer and its window are permanently attached.

The minibuffer window expands vertically as necessary to hold the text that you put in the minibuffer. If resize-mini-windows is t (the default), the window always resizes as needed by its contents. If its value is the symbol grow-only, the window grows automatically as needed, but shrinks (back to the normal size) only when the minibuffer becomes inactive. If its value is nil, you have to adjust the height yourself.

The variable max-mini-window-height controls the maximum height for resizing the minibuffer window: a floating-point number specifies a fraction of the frame's height; an integer specifies the maximum number of lines; nil means do not resize the minibuffer window automatically. The default value is 0.25.

The C-M-v command in the minibuffer scrolls the help text from commands that display help text of any sort in another window. M-<PAGEUP> and M-<PAGEDOWN> also operate on that help text. This is especially useful with long lists of possible completions. See section Using Other Windows.

Emacs normally disallows most commands that use the minibuffer while the minibuffer is active. (Entering the minibuffer from the minibuffer can be confusing.) To allow such commands in the minibuffer, set the variable enable-recursive-minibuffers to t.