
Mlulc.read(2M)     GRASS Reference Manual      Mlulc.read(2M)


NAME

     Mlulc.read - Extracts Landuse/Landcover data in the ASCII 
     Composite Theme Grid (CTG) data format distributed by the 
     USGS in to a working file for Mlulc.USGS
     (Map Development Tool)

SYNOPSIS

     dd [if=tapedev] ibs=input block size cbs=80 conv=unblock | Mlulc.read arg1 

DESCRIPTION

     Mlulc.read extracts USGS Land Use/Land Cover data distributed in
     the ASCII CTG format. Extracted data is placed into a file specified
     by arg1.  Mlulc.read should be used prior to using the GRASS tool
     program Mlulc.USGS.  

     The program reads the data from standard input allowing the user
     to pipe in the data from a file.  

     The data can also be read directly from the 1/2 inch magnetic tape
     distributed by USGS by using the UNIX command dd.
              
     if     the pathname of the input tape drive (usually
            /dev/rmt0)

     ibs    the physical blocking value of the data on tape,
            usually written on the tape spool.  If this value is
            unknown, run examine.tape prior to Mlulc.read.

     cbs    this is the conversion blocking factor for ASCII CTG 
            file and is by default 80

     conv   set conv to unblock when extracting ASCII CTG data 

     arg1   output file where the data will be stored in binary format.


EXAMPLES:

READING FROM A FILE:

        Mlulc.read outfile < infile

        This will read the data from infile and place the results into
        outfile.  Note that infile must be extracted from the USGS CTG
        1/2 magnetic tape using the dd command:

         dd if=/dev/rmt0 of=infile ibs=32000 cbs=80 conv=unblock

READING DIRECTLY FROM 1/2 INCH MAGNETIC TAPE:

        dd if=/dev/rmt0 ibs=32000 cbs=80 conv=unblock | Mlulc.read outfile

        This will extract data with a blocksize of 32000 from /dev/rmt0 
        32000 and put the results in the file outfile. 

SEE ALSO
     examine.tape[1], Mlulc.USGS
     manual entry for dd[1]

AUTHOR
     Kenneth Shepardson, Spectrum Sciences & Software, Inc. (904) 862-3031


GRASS 3.1           Spectrum Sciences & Software, Inc.             1



