Appendix L. History Commands

The Bash shell provides command-line tools for editing and manipulating a user's command history. This is primarily a convenience, a means of saving keystrokes.

Bash history commands:

1. history

2. fc

bash$ history
   1  mount /mnt/cdrom
    2  cd /mnt/cdrom
    3  ls
     ...
              

Internal variables associated with Bash history commands:

1. $HISTCMD

2. $HISTCONTROL

3. $HISTIGNORE

4. $HISTFILE

5. $HISTFILESIZE

6. $HISTSIZE

7. $HISTTIMEFORMAT (Bash, ver. 3.0 or later)

8. !!

9. !$

10. !#

11. !N

12. !-N

13. !STRING

14. !?STRING?

15. ^STRING^string^

Unfortunately, the Bash history tools find no use in scripting.

#!/bin/bash
# history.sh
# A (vain) attempt to use the 'history' command in a script.

history                      # No output.

var=$(history); echo "$var"  # $var is empty.

#  History commands are, by default, disabled within a script.
#  However, as dhw points out,
#+ set -o history
#+ enables the history mechanism.

set -o history
var=$(history); echo "$var"   # 1  var=$(history)

bash$ ./history.sh
(no output)             
              

The Advancing in the Bash Shell site gives a good introduction to the use of history commands in Bash.