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03/06/2019

How to Run and Execute Command When I Log Out Of Linux Session?



I‘m using CentOS 7 server. I need to run a command when I logout using ssh or bash shell. So in Linux and Unix-like systems, how can I run a command to execute when I log out my session?

You can easily get a command or shell script executed when you logout of the system. This is a shell specific feature and you need to add your command or script as per your shell version:
[donotprint][/donotprint]

  1. /bin/bash – BASH shell user create or update a file called .bash_logout in your home directory.
  2. /bin/csh or /bin/tcsh – CSH/TCSH shell user create or update a file called .logout in your home directory.
  3. Bourne / KSH Shell user need to setup a trap in .profile file as explained here.

Example: Run a command when I log out

Edit/append the following in your $HOME/.bash_logout (BASH) or $HOME/.logout (CSH/TCSH) file:

 ## clear the screen ##
clear
## Disk info ##
du -s $HOME
 
## Delete mysql cmd file ##
/bin/rm $HOME/.mysql_history
 
## add rest of the stuff here for bash

A note about Bourne / KSH Shell users

Edit/append the following in your $HOME/.profile file:

trap '. $HOME/.ksh_logout; exit' 0

Save and close the file. Finally create a text file called $HOME/.ksh_logout, enter:
$ vi $HOME/.ksh_logout
Add the following:

 ## Disk info ##
du -s $HOME
 
# Show date ##
date
 
## Sleep for some time so that I can read info ##
sleep 5
 
## clear the screen ##
clear
 
## Delete mysql cmd file ##
/bin/rm $HOME/.mysql_history
 
## add rest of the stuff here for ksh ##

A note about security

Please note that if you put too many commands or run a large script or script contains errors, an unauthorised person could gain access to your shell account by killing its execution. So, I recommend that you wait till you get a login prompt again. This hack will not work with GUI (KDE/Gnome/Xfce4) based login. This only works with a shell based session or ssh based session.

See man pages for more info – tcsh(1).

Posted by: SXI ADMIN

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

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