mjhjmtu

In Ubuntu 16.04 I've added the following code to /etc/bash.bashrc:

alias ll="ls -la --group-directories-first"

I then rebooted.

_{Note: I used /etc/bash.bashrc because I needed all aliases whatsoever in the one file and available for all users.}

My intention was to rewrite the "native" ll alias. Yet it wasn't changed; if I go to any dir that includes dirs and files, and I execute ll, I get a list without dirs being sorted above files. In other words.

What did I do wrong?

The ll alias is defined in the default .bashrc.

An alias definition is a command. Bash is an imperative language, it executes commands one after the other. If there are multiple definitions for the same alias, the alias is redefined each time the shell executes one of the definitions. Thus the last definition wins.

When bash starts, it reads the system file /etc/bash.bashrc before the user file ~/.bashrc. Thus a definition in ~/.bashrc overrides any definition of the same alias in /etc/bash.bashrc. You can't (sanely) do anything in /etc/bash.bashrc to prevent a redefinition in ~/.bashrc.

It doesn't make sense to impose convenience aliases on users. That's why ll is defined in ~/.bashrc and not in /etc/bash.bashrc. So instead of putting your preferred definition in the system file, put it in your user file.

You could change the default .bashrc — that's /etc/skel/.bashrc. This file is copied to a user's home directory when the user's account is created. Changing a file in /etc/skel has no impact on already-existing accounts. But even that is not a good idea since what you're defining is a personal preference.

/etc/bash.bashrc applies to all users

~/.bashrc only applies to the user in which home folder it is.

So, if you change the alias ll in /etc/bash.bashrc and run ll, you will get the output of the alias defined in ~/.bashrc, that is because ~/.bashrc has precedence over the definition in /etc/bash.bashrc.

To put it simply; Add new aliases in /etc/bash.bashrc, but for rewrites, change ~/.bashrc.

Edit:

If you really want to have it all in one file, remove all aliases from all ~/.bashrc ~/.bash_profile and/or ~/.profile files of all users, then add all the aliases to /etc/bash.bashrc this will create a global alias configuration without any issues.

Edit 2:

Create or edit /etc/skel/.bashrc and copy your default .bashrc config, so that when you create a new user, there are no default aliases set.

Thank you @user4556274 for the edit suggestion.

I'm fairly certain /etc/bash.bashrc isn't a thing. The file you are looking for is $HOME/.bash_profile OR $HOME/.profile Alternatively you could use $HOME/.bashrc but I think profile is the correct file for what you are trying to accomplish.

For an explanation of the difference between .bash_profile and .bashrc please see: http://www.joshstaiger.org/archives/2005/07/bash_profile_vs.html

To source .profile from .bash_profile add the following to your .bash_profile:

if [ -f ~/.profile ]; then
 . ~/.profile
fi

Another potential option would be to make ll into a function inside /etc/bash.bashrc instead of an alias which I believe the function will take precedence over any aliases set with the same name.

ll () 

 ls -la --group-directories-first