History Commands

Bash Unix Shell Scripting:

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