#!/bin/sh
#
#  tgrstrip [file] -- remove details from line chain file
#
#  Filters a line chain file to remove hydrology (water), pipelines,
#  powerlines, and minor roads, except when any of these coincides
#  with a major boundary line.  The effect of this is to produce a
#  much smaller file with less detail.

sed '
   /^[CEFH]..0/d
   /^A[4-9].0/d
' $*