Vector Cleaning

[Tom Hawkins]

We have created vector data in another package (Autocad) that we're bringing 
into GRASS.  Unfortunately, the data created does not always have nodes at 
line intersections (in Autocad).  When brought in as a DXF file, and 
inspected in v.digit, we can see all the missing nodes.  We used v.spag, and 
it did create nodes and cut off the resulting dangling lines, but only at 
those points where the lines actually touched (intersected).  Most of the 
lines that were supposed to be intersected are not in GRASS (they are in 
Autocad).  By zooming in a dozen or more times in v.digit, it's apparent 
that the lines are not touching (the distance between the endoint and the 
intended intersection point is around 0.0001 meters).  

Does GRASS have a program to extend dangling lines to another line, then 
break the line at that intersection?  There are far too many 
non-intersecting points in each file (and we have dozens of files) to do 
manually.  

Thanks for any help.

Tom Hawkins