How can I check the user command history in Unix?

Question

I know the 'history' command give me a list of the commands I have typed into the Unix terminal.

How do I see the command history for all of the users currently logged onto the system?

Solution 1

You get a list of currently logged in users in /var/run/utmp (see man 5 utmp). The history is stored in ~/.history or for bash user in ~/.bash_history. Other shells may use other history files, so it's not that easy to get really all information.

Furthermore, if a user is logged in multiple times, the .bash_history file is not always reliable.

To read the utmp file there is a "frontend" called who, so you could also write a shell-script to iterate over the currently logged in users.

Solution 2

echo $HISTFILE

Then view that file.

Comments

[Admin]

Not programming related. I suggest you ask on superuser.com.

[Admin]

There is no standard-tool to get the information, so I think it is programming (at least in the sense of 'scripting') - related.

[Dennis Williamson]

The current history is held in memory. The history file only shows what was written using history -a or similar or when a user exits the shell.

[DevSolar]

This works only if you have previously sourced that user's environment (as he might have set HISTFILE to something else).