I'm trying to implement two new key-value pairs for the
head= and tail= specify how many lines to display: That is,
tail=5 specifies to print the first 10 lines of the environment and last 5 lines.
(I know about the
lastline= options already available, but they are used to specify a 'middle' portion of the environment, which is a different problem.)
head= value to work isn't easy, but I think I understand how it can be done.
tail= value I'm having trouble with. In order to display the tail portion, I need to know where the tail portion starts, which presumes I know how many lines are in the environment to begin with.
Is there a method for that?