Variable: completion-auto-help

completion-auto-help is a customizable variable defined in minibuffer.el.gz.

Value

t

Documentation

Non-nil means automatically provide help for invalid completion input.

If the value is t, the *Completions* buffer is displayed whenever completion is requested but cannot be done. If the value is lazy, the *Completions* buffer is only displayed after the second failed attempt to complete. If the value is always, the *Completions* buffer is always shown after a completion attempt, and the list of completions is updated if already visible. If the value is visible, the *Completions* buffer is displayed whenever completion is requested but cannot be done for the first time, but remains visible thereafter, and the list of completions in it is updated for subsequent attempts to complete.

View in manual

Probably introduced at or before Emacs version 23.1.

Source Code

;; Defined in /usr/src/emacs/lisp/minibuffer.el.gz
(defcustom completion-auto-help t
  "Non-nil means automatically provide help for invalid completion input.
If the value is t, the *Completions* buffer is displayed whenever completion
is requested but cannot be done.
If the value is `lazy', the *Completions* buffer is only displayed after
the second failed attempt to complete.
If the value is `always', the *Completions* buffer is always shown
after a completion attempt, and the list of completions is updated if
already visible.
If the value is `visible', the *Completions* buffer is displayed
whenever completion is requested but cannot be done for the first time,
but remains visible thereafter, and the list of completions in it is
updated for subsequent attempts to complete."
  :type '(choice (const :tag "Don't show" nil)
                 (const :tag "Show only when cannot complete" t)
                 (const :tag "Show after second failed completion attempt" lazy)
                 (const :tag
                        "Leave visible after first failed completion" visible)
                 (const :tag "Always visible" always)))