Colour Errors / Warnings / Information in bash script

Question

So I have the following variables defined in /etc/bash.bashrc:

RS="\033[0m"    # reset
HC="\033[1m"    # hicolor
UL="\033[4m"    # underline
INV="\033[7m"   # inverse background and foreground
FBLK="\033[30m" # foreground black
FRED="\033[31m" # foreground red
FGRN="\033[32m" # foreground green
FYEL="\033[33m" # foreground yellow

And when I do an echo -e "$FRED Red" at the prompt, I actually get Red in red on gnome-terminal, but when I execute:

#!/bin/bash

echo -e "$FRED Red"
echo -e "$FYEL Yellow"
echo -e "$FGRN Green"

I get everything in the default colour even though $TERM is xterm-256color.

screenshot including exact output

What am I doing wrong?

_{Note: Eventually I want to echo Errors in red, Warnings in yellow and Info in green in my scripts.}

Answer 1

The variables in your /etc/bash.bashrc file are not exported. The file is read by any interactive non-login shell, but not by shell scripts (these are non-interactive).

Since the variables are not exported, they are not available in the environment of your script.

I would suggest not modifying the distribution-provided file /etc/bash.bashrc and instead:

• add the variables in the script itself (where they don't need to be exported), or
• add them (and export them) in your personal .bashrc file, or
• add them (and export them) in a separate .sh file under /etc/profile.d which would export the variables for any login shell. A login shell is started either by your terminal application, or by your graphical environment when you log in (or both).

If you add the variables anywhere other than in the script itself (in a file not explicitly sourced by the script), then the variables would not be available if you run the script from cron.