9.4 Minibuffer History
Every argument that you enter with the minibuffer is saved on a
minibuffer history list so that you can use it again later in
another argument. Special commands load the text of an earlier argument
in the minibuffer. They discard the old minibuffer contents, so you can
think of them as moving through the history of previous arguments.
- Move to the next earlier argument string saved in the minibuffer history
- Move to the next later argument string saved in the minibuffer history
- M-r regexp <RET>
- Move to an earlier saved argument in the minibuffer history that has a
match for regexp (
- M-s regexp <RET>
- Move to a later saved argument in the minibuffer history that has a
match for regexp (
The simplest way to reuse the saved arguments in the history list is
to move through the history list one element at a time. While in the
minibuffer, use M-p or up-arrow
previous-history-element) to “move to” the next earlier
minibuffer input, and use M-n or down-arrow
next-history-element) to “move to” the next later input.
These commands don't move the cursor, they bring different saved
strings into the minibuffer. But you can think of them as “moving”
through the history list.
The previous input that you fetch from the history entirely replaces
the contents of the minibuffer. To use it as the argument, exit the
minibuffer as usual with <RET>. You can also edit the text before
you reuse it; this does not change the history element that you
“moved” to, but your new argument does go at the end of the history
list in its own right.
For many minibuffer arguments there is a “default” value. In some
cases, the minibuffer history commands know the default value. Then you
can insert the default value into the minibuffer as text by using
M-n to move “into the future” in the history. Eventually we
hope to make this feature available whenever the minibuffer has a
There are also commands to search forward or backward through the
history; they search for history elements that match a regular
expression that you specify with the minibuffer. M-r
previous-matching-history-element) searches older elements in
the history, while M-s (
searches newer elements. By special dispensation, these commands can
use the minibuffer to read their arguments even though you are already
in the minibuffer when you issue them. As with incremental searching,
an upper-case letter in the regular expression makes the search
case-sensitive (see Search Case).
All uses of the minibuffer record your input on a history list, but
there are separate history lists for different kinds of arguments. For
example, there is a list for file names, used by all the commands that
read file names. (As a special feature, this history list records
the absolute file name, no more and no less, even if that is not how
you entered the file name.)
There are several other very specific history lists, including one for
command names read by M-x, one for buffer names, one for arguments
of commands like
query-replace, and one for compilation commands
compile. Finally, there is one “miscellaneous” history
list that most minibuffer arguments use.
history-length specifies the maximum length of a
minibuffer history list; once a list gets that long, the oldest element
is deleted each time an element is added. If the value of
t, though, there is no maximum length
and elements are never deleted.
history-delete-duplicates specifies whether to
delete duplicates in history. If the value of
t, that means when adding a new history element, all
previous identical elements are deleted.