How can I see Bash history from more than one terminal session in Ubuntu? [duplicate]

Question

Possible Duplicate:
Can history files be unified in bash?

I use Ubuntu Server 9.10 and I would like to be able to see my bash history for more than one terminal sessions. I.e. my last 200 commands or so, even if I have been logged out in between.

When I use the history I just see all commands from my actual terminal session. How can I see more command history from Bash? Is there any specific settings for bash that I should change from the default values in Ubuntu?

I don't have a ~/.bash_history file. But I have an ~/.bashrc with HISTCONTROL=$HISTCONTROL${HISTCONTROL+,}ignoredups and HISTCONTROL=ignoreboth

echo $HISTFILE
/home/sanoj/.bash_history
echo $HISTSIZE
500
echo $HISTFILESIZE
500
echo $HISTCONTROL
ignoreboth

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UPDATE: I am now trying Ubuntu Server 10.10 in VirtualBox. If I just turn off VirtualBox without the shutdown command, then next time when I boot, the commands from the last session is not saved in the history file.

The commands are only saved if I shutdown the machine with the shutdown command. E.g. shutdown -P 0.

This must be the reason to my problem. So I have to figure out how to save the command-history more often. E.g. after each command.

Answer 1

You can use

history -a

to immediately append the in-memory history to the history file. One terminal session can't see another's unless this is done or the other is exited.

You can use

history 200 | less

to see that number of entries.

In addition to HISTSIZE see the entry in the Bash man page concerning HISTFILESIZE.

Answer 2

Once you log out the history gets appended to the file ~/.bash_history. Have a look in there.

By default it will remember your last 500 commands. If you want to save more set the variable HISTSIZE in ~/.bashrc.

I also do add ignoredups to HISTCONTROL (with HISTCONTROL=$HISTCONTROL:ignoredup). This makes duplicate consecutive commands to be save only once.

Have a look at man 1 bash for what else you can tune about the history.

Answer 3

bash history is usually loaded when the shell begins running, and is saved when it is exited normally. You can use history -a and history -n to override this, but not automatically unless you abuse $PROMPT_COMMAND or something similar.

Answer 4

Sanoj, this really should "just work"; I don't think there is supposed to be anything special you need to do to enable this. It sounds like something is interfering with the normal course of events.

I would look in /etc/profile, /etc/bashrc (or perhaps /etc/bash.bashrc according to some sources), ~/.bash_profile, ~/.bashrc, ~/.bash_login, ~/.bash_logout, to see if there is anything that might be affecting the history (perhaps grep -i hist on each of the above files).

... In particular I wonder if you have something in ~/.bash_logout that removes the file.

Alternatively, is it possible that something is overriding the $HOME variable?