The echo area is a one line window which appears at the bottom of
the screen. It is used to display informative or error messages, and to
read lines of input from you when that is necessary. Almost all of the
commands available in the echo area are identical to their Emacs
counterparts, so please refer to that documentation for greater depth of
discussion on the concepts of editing a line of text. The following
table briefly lists the commands that are available while input is being
read in the echo area:
Cancel or quit the current operation. If completion is being read, this
command discards the text of the input line which does not match any
completion. If the input line is empty, it aborts the calling function.
The next group of commands deal with killing, and yanking
text. (Sometimes these operations are called cut and
paste, respectively.) For an in-depth discussion, see
Killing and Deleting in the GNU Emacs Manual.
Yank back a previous kill, removing the last yanked text first.
Sometimes when reading input in the echo area, the command that needed
input will only accept one of a list of several choices. The choices
represent the possible completions, and you must respond with one
of them. Since there are a limited number of responses you can make,
Info allows you to abbreviate what you type, only typing as much of the
response as is necessary to uniquely identify it. In addition, you can
request Info to fill in as much of the response as is possible; this
is called completion.
The following commands are available when completing in the echo area:
Insert as much of a completion as is possible. Otherwise,
display a window containing a list of the possible completions of what
you have typed so far. For example, if the available choices are:
bar
foliate
food
forget
and you have typed an ‘f’, followed by TAB, this
would result in ‘fo’ appearing in the echo area, since
all of the choices which begin with ‘f’ continue with ‘o’.
Now if you type TAB again, Info will pop
up a window showing a node called ‘*Completions*’ which lists the
possible completions like this:
3 completions:
foliate food
forget
i.e., all of the choices which begin with ‘fo’.
Now, typing ‘l’ followed by ‘TAB’ results in ‘foliate’
appearing in the echo area, since that is the only choice which begins
with ‘fol’.