When running commands in a Linux terminal, the system automatically saves a history of all the commands you have executed. This can be useful for recalling and reusing commands, but sometimes you may want to run a command without it being saved in your history. There are several ways to achieve this in Linux, and in this article, we will discuss some methods to run a command without keeping it in your history.

1. Using a space before the command:
One simple way to run a command without it being saved in your history is to prefix the command with a space. When you start a command with a space, the command will be executed as usual, but it will not be saved in your history. For example, instead of typing “ls” to list the files in a directory, type ” ls” with a space at the beginning.

2. Adding a space before the command in history:
If you have already run a command and realize that you want to exclude it from your history, you can use the control key shortcuts to edit the command before running it. Press “Ctrl + R” to search through your command history and find the command you want to run. When the command appears, press the right arrow key to move the cursor to the beginning of the line, then press the space bar. Now, when you run the command, it will not be saved in your history.

3. Using an alias:
Another method to run a command without keeping it in your history is to create an alias for the command. An alias is a custom shortcut for a command that allows you to run the command with a different name. To create an alias for a command, use the syntax “alias alias_name=’command'”. For example, to create an alias for the “ls” command, you can use the command “alias l=’ls'”. When you run the alias “l” instead of “ls”, the command will not be saved in your history.

4. Using the HISTCONTROL variable:
The HISTCONTROL variable in Linux allows you to control which commands are saved in your history. By setting the value of HISTCONTROL to “ignoreboth”, you can exclude commands that start with a space or commands that are duplicates from being saved in your history. To set the HISTCONTROL variable, use the command “export HISTCONTROL=ignoreboth” in your terminal. Now, any command that you run with a leading space will not be saved in your history.

In conclusion, there are several ways to run a Linux command without keeping it in your history. Whether you use a space before the command, edit the command in history, create an alias, or set the HISTCONTROL variable, you can easily exclude commands from being saved in your history. By using these methods, you can maintain the privacy and security of your command history while still executing commands in your Linux terminal.