Bash Using "trap" to react to signals and system events react on change of terminals window size
Example
There is a signal WINCH ( WINdowCHange), which is fired when one resizes a terminal window.
declare -x rows cols
update_size(){
rows=$(tput lines) # get actual lines of term
cols=$(tput cols) # get actual columns of term
echo DEBUG terminal window has no $rows lines and is $cols characters wide
}
trap update_size WINCH
