Re: [PATCH] Optimize usage of grep by passing -q

On Mon, Nov 16, 2015 at 10:43 PM, Stefan Beller [off-list ref] 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