XXX 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.