USGS Frequently Asked Questions

Answer:

• To read DLG files accessed on the EDC site into ARC/INFO requires two steps:
  1. These files are gzip compressed. Before anything else can be done, they must be uncompressed.
  2. These files are unblocked (all line feeds have been removed). To be read into Arc, these DLGs must be blocked to 80 characters per line.

  In the UNIX environment, the dd command can be used to block the DLGs. (dd if=old.dlg of=new.dlg ibs=1064 obs=80 cbs=80 conv=unblock)

  In the PC environment (DOS, win3.1, win95), use the DOS program CHOP to break the files into the appropriate length.

  If a C compiler is available for NT, the source code for a program called block.c can be obtained at http://thor-f5.er.usgs.gov/dxf/.