Unsupported grep -P option on Mac OS

[mbroadhead]

Hi,
Thanks for authoring this plugin.
Mac OS uses BSD grep rather than GNU grep. Because of this, grep's -P, --perl-regexp option is not available on Mac OS . This causes a bunch of error lines to be output every time you start a new shell with this plugin enabled:
usage: grep [-abcDEFGHhIiJLlmnOoqRSsUVvwxZ] [-A num] [-B num] [-C[num]]

Here are a few options to support Mac OS:

• Option Unsupported grep -P option on Mac OS #1: Use grep option -E, --extended-regexp rather than -P, --perl-regexp.
• Option Mode indicator isn't updating #2: Check for MacOS and if so use perl instead of grep. See stackoverflow.com for details on converting a grep call to a perl equivalent.

I'll look into this further when I get a chance.

My OS:

~ sw_vers
ProductName:	macOS
ProductVersion:	11.1
BuildVersion:	20C69

[jeffreytse]

Hi @mbroadhead

Hope you have a nice day. Also, thanks for your good help and support on this plugin.

Thanks and regards