his is an example of a search with
grepwith a coloured output:
To get this result open a terminal and use your favourite editor to change the file .bashrc in your home directoy, in this example I’ll use
$ vim ~/.bashrc
And add these 2 lines:
alias grep="grep --color=auto" export GREP_COLORS='0;31'
Save and try to use the
grep command. The result should be the same of the former screenshot and the following:
Let’s see how to change the colors. The colors are defined in the string:
The value “31” stands for red font as defined by the color table of the shell:
Color Foreground Background Black 30 40 Red 31 41 Green 32 42 Yellow 33 43 Blue 34 44 Magenta 35 45 Cyan 36 46 White 37 47
If we would like to see the text color in green, the value that we should use will be “32”.
Let’s see an example with the green color as background:
Exporting this variable:
where “30” is used to define the color of the foreground, in this case black, and “42” is the background, the color green.
And if you are on a different computer and you want to just have 1 colored output without changing the .bashrc file ?
No problem you can use
grep with the option
--color=auto to get the output with the default color that usually is a red foreground:
This option surround the matched (non-empty) strings, matching lines, context lines, file names, line numbers, byte offsets, and separators (for fields and groups of context lines) with escape sequences to display them in color on the terminal. The colors are defined by the environment variable GREP_COLORS. WHEN is never, always, or auto.
To see the various combinations of Foregrounds and Backgrounds just refer to THIS page.