Table of Contents
Introduction
How to Force history not to remember a particular command using HISTCONTROL ignorespace in Linux. When executing a command, you can use HISTCONTROL with ignorespace and precede the command with a space to ensure it’s ignored in your command history.
This might be tempting for junior sysadmins seeking discretion, but it’s essential to grasp how ignorespace functions. As a best practice, it’s generally discouraged to purposefully hide commands from your history, as transparency and accountability are crucial in system administration and troubleshooting.
What is HISTCONTROL?
HISTCONTROL is an environment variable in Linux that defines how your command history is managed. It allows you to specify which commands should be recorded in your history and which should be excluded. This can help you maintain a cleaner and more efficient command history.
ignorespace – An Option for HISTCONTROL
One of the settings you can use with HISTCONTROL is ignorespace. When ignorespace is included in the value of HISTCONTROL, any command line that begins with a space character will not be recorded in your command history. This can be incredibly handy for preventing sensitive information, such as passwords, from being stored in your history.
Working with HISTCONTROL ignorespace
Step 1: Check Your Current HISTCONTROL Setting
Before you start using HISTCONTROL with ignorespace, it’s a good idea to check your current HISTCONTROL setting. Open a terminal and run the following command:
echo $HISTCONTROL
This will display your current HISTCONTROL setting. If it’s empty or doesn’t include ignorespace, you can proceed to the next step.
Step 2: Set HISTCONTROL to ignorespace
To enable ignorespace in your HISTCONTROL, you can add the following line to your shell configuration file (e.g., ~/.bashrc for Bash users):
export HISTCONTROL=ignorespaceAfter making this change, be sure to reload your shell configuration or start a new terminal session for the changes to take effect.
Step 3: Test ignorespace
Now that you’ve set HISTCONTROL to ignorespace, you can test its functionality. Try entering a command with a leading space, like this:
ls -lNotice that the space at the beginning of the command is intentional. This command will not be recorded in your command history because of the ignorespace setting.
Step 4: Verify Your Command History
To verify that the command you just entered is not in your history, you can display your command history using the history command:
history
Conclusion
utilizing HISTCONTROL with ignorespace empowers you to better manage your Linux command history. This feature proves especially useful when excluding commands with sensitive data or temporary experiments. Understanding and harnessing HISTCONTROL ignorespace and its options, like ignorespace, enhances both the efficiency and security of your Linux command line experience.
Remember that these settings are user-specific, so individual configuration is necessary for each user on a multi-user system. Armed with this knowledge, you can exercise greater control over your command history and enhance your overall command line efficiency in Linux. You can Force history not to remember a particular command using HISTCONTROL ignorespace
