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Why are there so many duplicates in Bash history?
As you already know, each command we run in the terminal is saved in the history file. So executing the same commands over and over would fill up the history file. Sooner or later, you will end up with too many duplicate entries in history file. By default, 500 command entries are stored in the history file.
How to avoid duplicate entries in Bash history in Linux-ostechnix?
So, to avoid duplicate entries in Bash history in Linux, edit your ~/.bashrc file: Save and close the file. Here, the we prefixed the HISTCONTROL variable with “export”. It means the variable is available to all sub-processes. More details, here.
Where is the Bash history file in Linux?
In Linux systems that uses Bash, the commands are saved in ~/.bash_history file by default. You can check the location of the history file of your shell by running the following command: Here, HISTFILE is a variable that is used to define the name of the file in which command history is saved.
What happens the first time X is seen in Bash?
The first time a specific value of a line ($0) is seen, the value of x [$0] is zero. The value of zero is inverted with ! and becomes one. An statement that evaluates to one causes the default action, which is print. Therefore, the first time an specific $0 is seen, it is printed.
Is there a limit to the number of duplicate entries in history?
Sooner or later, you will end up with too many duplicate entries in history file. By default, 500 command entries are stored in the history file. In recent Ubuntu systems, the file size is 1000. Once the number of command entries crossed the default limit, the oldest entries will be eliminated from the history list.
How to clear the history file in Bash?
But it seems history -n is just buggy when export HISTCONTROL=ignoreboth:erasedups is in effect. Here we turn on dups erasing, switch history to custom file, clear the history. After all commands complete we have empty history file and one command at current history. Open second terminal and run those six command too.