Re: any plans for command substitution that preserves trailing newlines?

[Christoph Anton Mitterer]

On Wed, 2022-01-26 at 09:29 -0500, Chet Ramey wrote:
> That's the reason you should be careful -- setting LC_ALL may have
> other
> unwanted side effects, such as behavior controlled by LC_MESSAGES or
> LC_NUMERIC. You always need to understand the context.
> 
> As long as you set LC_ALL only for the scope of the assignment that
> strips
> the trailing byte, you should be able to avoid those side effects.

Sure that's anyway clear,... either restoring the old value afterwards,
or restoring it being unset (if it was so before).


> But to
> do that you have to make sure you save and restore all the locale
> variables (or use a function and local variables and let bash do it
> for
> you), especially if LC_ALL was previously unset.

That's however what I don't understand...

Why all the others, if I never touch them?



$ LANG="en_UK.UTF-8"
$ LC_TIME="en_US.UTF-8"
$ set | grep -E '(^LC_|^LANG)'
LANG=en_UK.UTF-8
LC_TIME=en_US.UTF-8

# that's the "old" state, then I set LC_ALL

$ LC_ALL=C
$ set | grep -E '(^LC_|^LANG)'
LANG=en_UK.UTF-8
LC_ALL=C
LC_TIME=en_US.UTF-8

# intermediate state, then I unset it again:

$ unset LC_ALL 
$ set | grep -E '(^LC_|^LANG)'
LANG=en_UK.UTF-8
LC_TIME=en_US.UTF-8
$ 

Back to old state,... none of the other vars were changed.

So if I just touch LC_ALL, why do I "have to make sure you save and
restore **all** the locale variables"?


Thanks,
Chris.