#GREP IP ADDRESS AUTH.LOG HOW TO#

If you want to verify that a given user has been logged into the system for a period of time, use the following format. If you want to verify who has been logged into the system for a particular period of time, use the following format. Replace ‘user_name’ with the desired username you want to verify. If you want to see the history of a particular user, use the below command. If it has a lot of values, use less or more command to view them page wise. Run the ‘last’ command without any arguments to view the history of all the successful login in the system. A pty (pseudo terminal device) is a terminal device that is emulated by another program such as putty, xterm or screen, etc.ġ) Checking login history of all logged users in Linux.A tty stands for TeleTYpe is a native terminal device (It could be a server/system console).You may have seen pts and tty values in the who command output and the below explanation will show the difference between them. Lastb command is the same as last command, by default it shows the log of the file ‘/var/log/btmp’ file, which contains all bad login attempts. Last command searches the user information from the ‘/var/log/wtmp’ file and displays a list of all users who have logged in and out since the file was created. /var/log/btmp: It contains bad login attempts.Īlternatively, user login information can be verified using the aureport tool, which generates summary reports of the user’s login history.

The last command uses this file to display the information. It keeps the users login and logout history.

/var/log/wtmp: It contains historical utmp.

Who command is used to fetch the information from the file.

/var/run/utmp: It contains information about the users who are currently logged onto the system.For example, if some files are removed at a particular time and we can enquire the users who logged into the system during that time for first-level troubleshooting.Īll source files are located in the following location and these are binary files that cannot be viewed in any text editor. It will help us to analyze certain types of issues. It contains a bunch of useful information about the user such as user name, name of the terminal connected, source IP (from which IP address the user has accessed the system), date, time and how long the user has been logged into the system. However, we will also provide you with a summary of the other commands.

#GREP IP ADDRESS AUTH.LOG HOW TO#

This can be done in multiple ways and we will show you how to check the user login history in detail using the last command in this article. Linux is a multi-user operating system and more than one user can be logged into a system at the same time.įor some reason, you may be required to check login history to identify those who have logged into the system recently or within a certain period of time.

Grep ip address auth.log