Shell Programming and Scripting

I have tested different versions of GNU grep.
Don, you are right, the --color=always puts some default color codes even if the output is not a terminal.
Correct is --color=auto.
Therefore, the .bashrc/.profile should have the environment

Code:

export GREP_OPTIONS='-irs --color=auto --line-number --exclude-dir=.git'

that is still inherited by scripts,
or the alias

Code:

alias grep='grep -irs --color=auto --line-number --exclude-dir=.git'

that is not inherited by scripts (recommended).
It's a pity that every shell script should have

Code:

unset GREP_OPTIONS

for safety.
GNU is not Unix, and suffers from creeping featurism