Question

grep doesn’t allow setting color by

grep --color='1;32'

(1 meaning bold, and 32 meaning green). It has to use GREP_COLOR by

export GREP_COLOR='1;32'

and then use grep --color

How do we alias or write a function for grep so that we have 2 versions of grep (say, grep and grepstrong), one for usual green font, and the other one, green font with a black (or white) background?

alias grep='export GREP_COLOR="1;32"; grep --color'

won’t work because if we use

grep some_function_name | grep 3

then the above alias will generate results of the grep, and pipe into export, so the second grep won’t get any input at all and just waiting there.

Answer 1

With bash, you can set environment variables for just a single command by prepending the command with “key=value” pairs:

GREP_COLOR='1;32' grep --color <whatever>

Example:

echo foo | VAR=value bash -c 'read line; echo $VAR: $line'

So in your case, just say:

alias grep='GREP_COLOR="1;32" grep --color'