grc (generic colouriser)

grc  provides  two programs:  grc and grcat.  The main is grcat, which
acts as a  filter,  i.e.  taking standard input,  colourising  it  and
writing to standard output.  grcat  takes  as  a parameter the name of
configuration file.

NOTE: to use, add following lines into your ~/.bashrc, ~/.zshrc  or in
~/.config/fish/config.fish:

[[ -s "/etc/profile.d/grc.bashrc" ]] && source /etc/profile.d/grc.bashrc
[[ -s "/etc/profile.d/grc.zsh" ]] && source /etc/profile.d/grc.zsh
[[ -s "/etc/profile.d/grc.fish" ]] && source /etc/profile.d/grc.fish