Well, you may call this as a Linux tip for the day. I’m going to share a tip that lets you to execute a command in shell prompt and does not save it in command history. Generally any command you execute in shell gets stored in a command history and the ‘history‘ command will display the list of commands that you had executed in the past. That’s quite useful. But what if you want to execute a command and then prevent it from storing in a command history?
Answer:
Executing any command starting with <space> will not be stored in command history.
For e.g.,
#<space> hostname
The above command will display the hostname of the machine, but the command itself is not stored in the command history.
But wait, you should control HISTORY (via HISTCONTROL environment variable). Check what is being set in HISTCONTROL as below:
#echo $HISTCONTROL
Now, set HISTCONTROL as below:
#export HISTCONTROL=ignorespace
Or you may add the above line to $HOME/.bashrc.
# .bashrc # Source global definitions if [ -f /etc/bashrc ]; then . /etc/bashrc fi # User specific aliases and functions export HISTCONTROL=ignorespace
The above command controls the command history to ignore space. So whenever a command is executed with a space in the front, it will not be stored in history.
