The C shell and bash
can save copies of the previous command lines
Later, you can ask for a copy of some or all of a previous command line.
That can save time and retyping.
This feature is called history substitution
, and it's done when you type a string
that starts with an exclamation point (
You can think of it like
variable substitution (
command substitution (
the shell replaces what you type (like
) with something else
(in this case, part or all of a previous command line).
is an introduction to shell history.
These articles show lots of ways to use history substitution:
We start with favorite uses from several contributors - articles
starts with a quick introduction, then covers the
full range of history substitutions with a series of examples that show the
different kinds of things you can do with history.
(Back in article
are examples of csh
Many of these can be used to edit history substitutions.)
See an easy way to repeat a set of csh
commands in article
Each shell saves its own history.
To pass a shell's history to another shell, see articles
You don't have to use an exclamation point (
) for history.
shows how to use some other character.
The Korn shell does history in a different way.
introduces part of that: command-line editing in ksh
One last note:
putting the history number in your prompt (7.2
makes it easy to re-use commands that haven't scrolled off your screen.