4am, get some sleep and look at this later!

When your read consider that even if the function is defined internal to your script (via source or defined directly) it can still dynamically integrate the terminal width.

Here is a little demo of what I'm talking about. I've used MYCOLS instead of the shell COLUMNS variable as it's easier to change and demonstrate:

Code:

function tui-printf
{
   local size1
   WIDTH=${MYCOLS:-$(tput cols)}
   printf "Width = %d\n" "$WIDTH"

   printf "before: Size1 = %d, Size2 = %d\n" ${size1:-0} ${size2:-0}
   ((size1=WIDTH/8))
   ((size2=WIDTH/8))
   printf "after: Size1 = %d, Size2 = %d\n" ${size1:-0} ${size2:-0}
}

tui-printf
MYCOLS=120
tui-printf
unset MYCOLS
tui-printf

Also note above that you use local to control if the values in variables will carry over from the last call or not.