41.4.1 Displaying Messages in the Echo Area

This section describes the standard functions for displaying messages in the echo area.

Function: message format-string &rest arguments

This function displays a message in the echo area. format-string is a format string, and arguments are the objects for its format specifications, like in the format-message function (see Formatting Strings). The resulting formatted string is displayed in the echo area; if it contains face text properties, it is displayed with the specified faces (see Faces). The string is also added to the *Messages* buffer, but without text properties (see Logging Messages in *Messages*).

Typically grave accent and apostrophe in the format translate to matching curved quotes, e.g., "Missing `%s'" might result in "Missing ‘foo’". See Text Quoting Style, for how to influence or inhibit this translation.

In batch mode, the message is printed to the standard error stream, followed by a newline.

When inhibit-message is non-nil, no message will be displayed in the echo area, it will only be logged to ‘*Messages*’.

If format-string is nil or the empty string, message clears the echo area; if the echo area has been expanded automatically, this brings it back to its normal size. If the minibuffer is active, this brings the minibuffer contents back onto the screen immediately.

(message "Reverting `%s'..." (buffer-name))
 -| Reverting ‘subr.el’...
⇒ "Reverting ‘subr.el’..."

---------- Echo Area ----------
Reverting ‘subr.el’...
---------- Echo Area ----------

To automatically display a message in the echo area or in a pop-buffer, depending on its size, use display-message-or-buffer (see below).

Warning: If you want to use your own string as a message verbatim, don’t just write (message string). If string contains ‘%’, ‘`’, or ‘'’ it may be reformatted, with undesirable results. Instead, use (message "%s" string).

The following facilities allow users and Lisp programs to control how echo-area messages are displayed.

Variable: set-message-function

If this variable is non-nil, it should be a function of one argument, the text of a message to display in the echo area. That function will be called by message and related functions. If the function returns nil, the message is displayed in the echo area as usual. If the function returns a string, that string is displayed in the echo area instead of the original message. If the function returns any other non-nil value, that means the message was already handled, so message will not display anything in the echo area.

The default value calls set-minibuffer-message, described below.

Variable: clear-message-function

If this variable is non-nil, it should be a function of no arguments; message and related functions call it when their argument message is nil or the empty string, to clear the echo area.

Usually this function is called when the next input event arrives after displaying an echo-area message. The function is expected to clear the message displayed by its counterpart function specified by set-message-function, but doesn’t have to. If the function wants the echo area to remain uncleared, it should return the symbol dont-clear-message; any other value will result in the echo area being cleared.

The default value is the function that clears the message displayed in an active minibuffer.

User Option: set-message-functions

The value of this user option is a list of functions to be called for handling display of echo-area messages. Each function is called with one argument, the text of the message to display. If the function returns a string, that string replaces the original message, and the next function in the list is called with the new message text. If the function returns nil, the next function in the list is called with the same text; if the last function in the list returns nil, the message text is displayed in the echo area. If the function returns a non-nil value that is not a string, the message is considered to be handled, and no further functions in the list are called.

The three useful functions to be put in the list that is the value of this option are described below.

Function: set-minibuffer-message message

This function displays message in the echo-area when the minibuffer is not active, and at the end of the minibuffer when the minibuffer is active. However, if the text shown in the active minibuffer has the minibuffer-message text property (see Properties with Special Meanings) on some character, the message will be displayed before the first character having that property.

This function is by default the only member of the list in set-message-functions.

Function: inhibit-message message

If an echo-area message matches any regexp in the list that is the value of the user option inhibit-message-regexps, this function suppresses the display of that message and returns a non-nil value that is not a string. Thus, if this function is in the list set-message-functions, the rest of the functions in the list will not be called when message matches the regexps in inhibit-message-regexps. To ensure a matching message will never be displayed, make this function be the first element of the list in set-message-functions.

Function: set-multi-message message

This function accumulates several echo-area messages emitted one after another, and returns them as a single string in which individual messages are separated by newlines. Up to multi-message-max recent messages can be accumulated. The accumulated messages are discarded when more than multi-message-timeout seconds have elapsed since the time the first message was emitted.

Variable: inhibit-message

When this variable is non-nil, message and related functions will not display any messages in the Echo Area. Echo-area messages are still logged in the *Messages* buffer, though.

Macro: with-temp-message message &rest body

This construct displays a message in the echo area temporarily, during the execution of body. It displays message, executes body, then returns the value of the last body form while restoring the previous echo area contents.

Function: message-or-box format-string &rest arguments

This function displays a message like message, but may display it in a dialog box instead of the echo area. If this function is called in a command that was invoked using the mouse—more precisely, if last-nonmenu-event (see Information from the Command Loop) is either nil or a list—then it uses a dialog box or pop-up menu to display the message. Otherwise, it uses the echo area. (This is the same criterion that y-or-n-p uses to make a similar decision; see Yes-or-No Queries.)

You can force use of the mouse or of the echo area by binding last-nonmenu-event to a suitable value around the call.

Function: message-box format-string &rest arguments

This function displays a message like message, but uses a dialog box (or a pop-up menu) whenever that is possible. If it is impossible to use a dialog box or pop-up menu, because the terminal does not support them, then message-box uses the echo area, like message.

Function: display-message-or-buffer message &optional buffer-name action frame

This function displays the message message, which may be either a string or a buffer. If it is shorter than the maximum height of the echo area, as defined by max-mini-window-height, it is displayed in the echo area, using message. Otherwise, display-buffer is used to show it in a pop-up buffer.

Returns either the string shown in the echo area, or when a pop-up buffer is used, the window used to display it.

If message is a string, then the optional argument buffer-name is the name of the buffer used to display it when a pop-up buffer is used, defaulting to *Message*. In the case where message is a string and displayed in the echo area, it is not specified whether the contents are inserted into the buffer anyway.

The optional arguments action and frame are as for display-buffer, and only used if a buffer is displayed.

Function: current-message

This function returns the message currently being displayed in the echo area, or nil if there is none.