Tool -flag considered harmful (was: grep replacement)

[andrew at alice.UUCP]

there are some technical problems with printing context, particluarly
if you want regular expreesion-defind contexts. it means you have to be
able to run the sodding regexp stuff backwards thru the text. it also
means keeping a lot of buffer which is more than a little repugnant.
despite all this, it is feasible but not trivial to add context stuff.
i won't do it though.