Not understanding when to use ~/.bashrc, /etc/profile ,~/.bash_profile or ~/.profile?

[shivajikobardan]

I've read tidbits of pages from around 10 books, and I can safely say I am even more confused than before. Earlier I'd just set everything in .bashrc file. LOL.

Say I've scenarios like these:

1) I want to set system variables for user "jacky", what should I use?

2) I want to set system variables for all users, what  should I use?

3) I want to set alias for user "jacky", what should I use?

4) I want to set alias for all users, what should I use?

What are interactive/non-interactive login/non-login shells?

I've asked chatgpt but it gave me convoluted reply.  So, it was not very clear.

 

[C2dan88]

4 hours ago, shivajikobardan said:

1) I want to set system variables for user "jacky", what should I use?

3) I want to set alias for user "jacky", what should I use?

For users typically add custom variable/aliases to ~/.profile or relevant .**shell**rc file (ie .bashrc for bash .zshrc for zsh etc)

 

 

4 hours ago, shivajikobardan said:

2) I want to set system variables for all users, what  should I use?

4) I want to set alias for all users, what should I use?

For setting system wide variable/aliases for all users either modify /etc/profile or create a new shell script in /etc/profile.d/

 

[Raytsou]

The original unix shell terminal, named "Bourne Shell", launched via `sh`; `bash` extends that, called "Bourne-again shell".

`.profile` is what `sh` looks for. Tbh I had to look this up bc I'd never even heard of `.profile`.

`/etc/.profile` is the system wide profile and affects everyone.

`.bash_profile` is the configuration profile for just the logged-in user

`.bashrc` is the profile used if `bash` is launched in non-login mode

 

So when you launch `bash`, it will first run `/etc/.profile`, then depending on if you invoked `bash` as login or non-login mode, it will run either the `.bash_profile` or the `.bashrc`. If it can't find a `.bash_profile`, it defaults back to `.profile`