bug-bash
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: different exit codes in $? and ${PIPESTATUS[@]}


From: Dan Douglas
Subject: Re: different exit codes in $? and ${PIPESTATUS[@]}
Date: Mon, 15 Oct 2012 09:47:30 -0500
User-agent: KMail/4.8.3 (Linux/3.4.6-pf+; KDE/4.8.3; x86_64; ; )

This makes a lot of sense. Thanks for the nice explanation and link!

On Sunday, October 14, 2012 01:10:17 PM Chet Ramey wrote:
> It's a little easier to see how ! ! is a no-op that way.

The "negated false pipeline" isn't something I'd given much thought to. It 
turns out "! !" is an even faster noop than the previous fastest I'd found ( 
looping a few million times: "! !" is slightly faster than "<()", which is 
slightly faster than ":"). Only bash/ksh seem to accept either a bare "!" or 
"! !" though. Bash interestingly accepts "! !<newline>cmd" and "{ ! !; }; 
cmd", but not "! !; cmd". 

Also I may as well overload this mail by reporting that nearly every issue 
I've ever sent to this list over the last year or so (that turned out being 
"legitimate") appears to have been addressed in devel (at least, according to 
a few minutes of testing). Thanks! :)
-- 
Dan Douglas



reply via email to

[Prev in Thread] Current Thread [Next in Thread]