From: Mikael Magnusson Date: Tue, 17 Nov 2015 00:59:11 GMT Subject: Re: [PATCH] Optimize usage of grep by passing -q Message-ID: In-Reply-To: <1447710209-13117-1-git-send-email-sbeller@google.com> On Mon, Nov 16, 2015 at 10:43 PM, Stefan Beller wrote: > Instead of redirecting all grep output to /dev/null, we can just > pass in -q instead. This preserves the exit code behavior, but is faster. > As grep returns true if it finds at least one match, grep can exit promptly > after finding the first line and doesn't need to find more occurrences > which would be redirected to /dev/null anyways. > > This is true for the gnu version of grep. I am not sure if all > versions of grep support this optimization. In case it is not, > we'd revert this patch. POSIX specifies -q, so you should be fine. http://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html -- Mikael Magnusson