terminal width

If I have a ragged array that I want to cut down to terminal width this 
is fine for each line:

output[line_number]=$input[1, $COLUMNS]

... if there are no color codes or tabs.  If there are, the predictable 
thing happens.  Using 'cut' has exactly the same problem.  I doubt the 
shell can be asked to deal with that, but I'll ask anyway.  Could be 
that ncurses, or something, will handle it.  Or maybe somebody knows of 
a utility that can.  I understand that it's a can of worms tho.