Parameter expansion
by Faki from LinuxQuestions.org on (#5SW8H)
Is this how I can set `ctp` if no default has been used
Code:local ctp=""
local -r wht=$(tput setaf 7)
: ${ctp:="$wht"}
Code:local ctp=""
local -r wht=$(tput setaf 7)
: ${ctp:="$wht"}