command history is a quick and dirty script created to show what commands were executed on the day command history is run. Its purpose is to help sysadmins conveniently keep a watchful eye over their users to make sure they aren't snooping around too much, and is best run from crontab to produce mail output each day.
A command processor feature which retains the commands you have executed from the command prompt, so that they can be recalled, optionally modified, and reexecuted later.
A record of the most recent commands issued from the keyboard is retained in the command history . These commands can be replayed using the !: command, or deleted from the buffer using the /: command. The command history can also be saved to a file using the KEEP: command.