How to Use Different Commands in Linux to Clear History

How to Check the Bash History?

Before clearing your history, you can check the commands that have been recorded by using the history command:

$ history

This will display a list of recent commands executed in the terminal, each with a line number.

To view the .bash_history file directly, you can use the cat command:

$ cat ~/.bash_history

There are several ways to clear Bash command history. You can clear specific commands, clear all history for the current session, or completely delete the history file.

Below are the methods:

Commands Used in Linux to Clear History for a Specific Entry

If you want to clear a specific history, you can use the history -d command. This command is one of the useful commands in Linux to clear history, as it allows you to delete a particular entry from the history list without affecting the rest.

• Open the terminal and execute the following command to display the current command history:

history

This will list all previously executed commands with their respective line numbers.
• Identify the line number of the command you want to remove. For example, if the command you want to remove is on line 15, note down the number.
• Execute the following command to delete the specific command from the history:

history -d 15

• To ensure the history file is updated with the removed command, run the following command:

history -w

This will overwrite the .bash_history file with the current history in memory, making sure the changes are saved.

Commands Used in Linux to Clear History for the Current Session

If you want to clear all the commands from the current session without deleting the .bash_history file, you can use the history -c command. This is one of the useful commands in Linux to clear history, as it clears the current session’s history, but it does not affect the history saved in the .bash_history file.

• Open the terminal and execute the following command to clear the session history stored in memory:

history -c

• To ensure the cleared history overwrites the history file, run:

history -w

• Close the terminal and reopen it to confirm that the history has been completely cleared.

Commands Used in Linux to Clear History Permanently

If you want to permanently clear all the history (including the .bash_history file), follow these steps:

• Open the terminal and clear the current session history by executing:

history -c

• Save the cleared session history to overwrite the .bash_history file:

history -w

• Delete the .bash_history file entirely by running:

rm ~/.bash_history

Commands Used in Linux to Prevent Bash from Saving History

If you want to prevent Bash from saving commands to the history file temporarily, you can unset the HISTFILE variable:

• Open the terminal
• Run the following command to stop Bash from saving commands to the .bash_history file:

unset HISTFILE

This removes the link between the session and the history file, so no commands will be saved during the session.
• To prevent storing commands temporarily during the session, set the history size to zero with this command:

export HISTSIZE=0

This ensures no history is retained in memory for the session.
• To make these changes permanent, edit the .bashrc file in the home directory. Run the following lines at the end of the file:

unset HISTFILE  
export HISTSIZE=0

• Save the file, close the editor, and apply the changes by running the following command:

source ~/.bashrc

Commands Used in Linux to Automatically Clear History on Logout

To clear the history automatically when logging out, follow these steps:

• Open your ~/.bash_logout file in a text editor.

nano ~/.bash_logout

• Run the following lines to the file:

history -c
history -w

• Save the file and exit the editor.

This will ensure that the history is cleared every time you log out. The history -c command clears the in-memory history, and the history -w command writes the cleared history to the .bash_history file.