Re: SHELLOPTS=xtrace security hardening

[Stephane Chazelas]

2015-12-15 09:01:05 -0500, Chet Ramey:
[...]
> > Mind explaining this one?
> > I can't seem to write to HISTFILE in a non-interactive shell, or am i
> > missing something?
> 
> You just need to enable history (set -o history).  History is independent
> of whether or not the shell is interactive; it's just enabled by default
> in interactive shells.
[...]

BTW:

$ bash -o history -o histexpand -c 'echo !!'
!!
$ bash -o history -o histexpand <<< 'echo !!'
!!
$ SHELLOPTS=history:histexpand  bash -c 'echo !!'
!!
$ SHELLOPTS=history:histexpand bash <<< 'echo !!'
bash: line 1: !!: event not found
$ SHELLOPTS=history:histexpand bash <(<<<'echo !!')
/proc/self/fd/11: line 1: !!: event not found
$ bash -o history -o histexpand <(<<< 'echo !!')
!!

(also note that when there is an error, the exit status is 0)

-- 
Stephane