Subject: bug#29354: GREP_OPTIONS not processed

From: Paul Eggert <[email-masked]>
Date: Sat, 18 Nov 2017 19:10:13 -0800

Dennis wrote:
> Running grep 2.20 on Debian Jessie.
> 
> Apparently grep is not processing the GREP_OPTIONS
> environment variable.

That's odd; in the master sources GREP_OPTIONS still works; it's just that it's 
deprecated and issues a warning. Perhaps Debian has changed that?

Anyway, GREP_OPTIONS is deprecated because of correctness and security issues 
caused by having environment variables change the behavior of standard commands. 
If you want your grep to default to -i, you can create a script called 'grep' 
that invokes /usr/bin/grep -i, and put your script in your PATH before /usr/bin.