[SOLVED] bash invocation question

K4rolis · 09-13-2016, 04:18 PM

Hi,

I've noticed an interesting thing that is not clear to me - why most of the variables from /etc/profile propagate all the way to interactive shells (which is what I would expect), but not the PS1? Where does it get overwritten from

Code:

PS1='\u@\h:\w\$ '

to

Code:

PS1='\s-\v\$ '

?

I actually experimented with exporting a TESTVAR that I defined in /etc/profile, which, as do other variables defined there, propagate to interactive shells for a regular user.

Am I being silly or is this inconsistent?

STDOUBT · 09-13-2016, 07:19 PM

Off the top of my head, /etc/profile will be overridden by whatever variables are contained in a user's (or even root's) ~/.profile

Richard Cranium · 09-13-2016, 07:24 PM

There's a lot of stuff in /etc/profile.d too.

wpeckham · 09-13-2016, 08:10 PM

To get the full story, you will want to investigate the BASH documentation, the disto documentation (luckily, slack has GREAT documents), and do a little local investigation on your own machine. A variable can be set in a LOT of places, but the order and hierarchy will determine which value appears when the session opens.

BTW: the behavior is also different for different shells. The specific shell, and to some extent the version, will change the answers.

This is FUN!

vonbiber · 09-14-2016, 12:01 AM

Quote:

Originally Posted by STDOUBT

Off the top of my head, /etc/profile will be overridden by whatever variables are contained in a user's (or even root's) ~/.profile

and, if you are on a x-session, in ~/.bashrc

K4rolis · 09-14-2016, 01:18 AM

So my brute-force approach to work this out has not worked very well: I've grepped everything (i.e. the root recursively) for 'export.*PS1' (which is, I am aware, bash-specific), and the only hits that I had was in /etc/profile and in /etc/rc.d/rc.S (as well as documentation), but the one in rc.S seems to only be used in case of system repairs (and not general case), so I'm tempted to assume that it is irrelevant.

I do not have any local .profile or .bashrc that touch PS1.

55020 · 09-14-2016, 02:26 AM

http://superuser.com/questions/66306...d-variable-ps1

K4rolis · 09-14-2016, 02:45 AM

55020, this completely answers my question and is consistent with what I suspected. Thank you!

Marking as solved.