Is there any env variable to turn --color (and the like) on for all commands?

Question

I do use aliases to turn on color for some commands by default. But I'm wondering if there's an easier way at telling my system, color is supported, don't make me use --color for grep, ls, etc.

Answer 1

FreeBSD has CLICOLOR.

On Linux and any other system with GNU tools, you need to set LS_COLORS, GREP_COLOR, and GREP_OPTIONS='--color=auto', but even then you still need to run ls --color=auto. Run info coreutils 'ls invocation' for more details.

The easiest way I know to avoid typing --color on Linux is to make ls run ls --color=auto using an alias.

This is what I put in my .bashrc (well, really my .env, but it's like .bashrc) to make it happen by default:

# set default flags
if grep --color=auto --quiet "" "$HOME"/.bashrc >/dev/null 2>&1
then
  alias grep='grep --color=auto'
fi
if ls --color=never --directory / >/dev/null 2>&1
then
  # enable colors with GNU ls
  alias ls='ls --color=auto'
else
  alias ls='ls -F'
fi

Answer 2

There isn't a standard for forcing colours.

CLICOLOR is increasingly common, and there's an attempt to standardise it too.

You can alias commands to provide the --color=auto (or equivalent) flag by default in your .bashrc, but you'll need to find the relevant flag for each command.