LLSEARCH(1)						      General Commands Manual						       LLSEARCH(1)

NAME

       llsearch - Search a GNIS file for place names within a given block of latitude/longitude

SYNOPSIS

       llsearch [-L] | [latitude_low longitude_low latitude_high longitude_high]

DESCRIPTION

       The U.S. Geological Survey supports sites on the Internet with Geographic Names Information System (GNIS) files.  These files contain lists
       of place names, complete with their latitude/longitude and other information.  There are separate files for each of the	U.S.  states,  and
       each  file  contains  many, many, many place names.  If you want to use this data with drawmap, it is useful to reduce the data to only the
       items that you need.  Llsearch lets you filter a GNIS file and winnow out only those place names that fall  within  the	latitude/longitude
       boundaries  that  you  specify.	 (You  may  want to specify boundaries that are a tiny bit larger than what you are interested in, so that
       numerical quantization doesn't eliminate locales that fall exactly on your boundaries.)

       Latitudes and longitudes are positive for north latitude and east longitude, and negative for south latitude and west longitude.   Llsearch
       expects	you  to enter them in decimal degrees.	(The latitudes and longitudes in the GNIS file are in degrees-minutes-seconds format, fol-
       lowed by 'N', 'S', 'E', or 'W'.	However, there are two available file formats, and one of the formats also contains  the  latitudes/longi-
       tudes in decimal degrees.)  Typical usage is as follows:

       gunzip -c california.gz | llsearch 33 -118 34 -117 > gnis_santa_ana_west

       If you enter the "-L" option, the program will print some license information and exit.

       Once  you  have	reduced  the  data to some subset of interest, you can search for particular items via the grep or perl commands, or other
       search commands, or you can simply edit the results with your favorite text editor.  Search commands are useful in reducing the sheer  vol-
       ume  of	data  to a more manageable size (by extracting, say, all mountain summits or all streams), but you will probably ultimately end up
       looking through the remaining data manually.  The individual records contain codes, such as "ppl" for populated places,	and  "summit"  for
       mountain tops, that can help you pick and choose.

       There  is  considerable redundancy in place names, and human intelligence is useful in sorting things out.  While I was writing drawmap and
       llsearch, I frequently gazed out my office window, where I could spot at least two, and possibly three Baldy  Mountains.   There  are  also
       quite  a  few Beaver Creeks, Bear Canyons, Saddle Buttes, and Springfields out there.  By taking a close look at the information associated
       with each place name, you can find the particular locations that interest you.

SEE ALSO

       drawmap(1)

								   Jul 24, 2001 						       LLSEARCH(1)