some modern updates

contours/clip-2009.awk

@@ -1,5 +1,5 @@
-#!/usr/bin/awk -f
-
+#!/usr/bin/env -S awk -f
+#
 # this file works with SEZP from circa 2009, where x coordinate (the 6-digit one)
 # is first, and the field separator is ' ' or more spaces.
 $1 > xmin && $1 < xmax && $2 > ymin && $2 < ymax {