.. _shapefiles:

*****************************************************************************
 ESRI Shapefiles (SHP)
*****************************************************************************

Also known as ESRI ArcView Shapefiles or ESRI Shapefiles.  ESRI is the company 
that introduced this format.  ArcView was the first product to use shapefiles.

File listing
--------------

Shapefiles are made up of a minimum of three similarly named files, with different suffixes::

	Countries_area.dbf
	Countries_area.shp
	Countries_area.shx

Data Access / Connection Method
---------------------------------

Shapefile access is built directly into MapServer.  It is also available 
through OGR, but direct access without OGR is recommended and discussed here. 
The path to the shapefile is required.  No file extension should be specified. 
Shapefiles only hold one layer of data, therefore no distinction needs to be 
made.

OGRINFO Examples
--------------------

* The directory can serve as a data source.
* Each shapefile in a directory serves as a layer.
* A shapefile can also be a data source.  In this case the layer has the 
  same prefix as the shapefile.

Using ogrinfo on a directory with multiple shapefiles::

	> ogrinfo /data/shapefiles/
	INFO: Open of `/data/shapefiles/'
	using driver `ESRI Shapefile' successful.
	1: wpg_h2o (Line String)
	2: wpg_roads (Line String)
	3: wpg_roads_dis (Line String)
	4: wpgrestaurants (Point)

Using ogrinfo on a single shapefile::

	> ogrinfo /data/shapefiles/Countries_area.shp
	Had to open data source read-only.
	INFO: Open of `Countries_area.shp'
	using driver `ESRI Shapefile' successful.
	1: Countries_area (Polygon)

Using ogrinfo to examine the structure of the file/layer::

	> ogrinfo -summary /data/shapefiles/Countries_area.shp Countries_area
	Had to open data source read-only.
	INFO: Open of `Countries_area.shp'
	using driver `ESRI Shapefile' successful.

	Layer name: Countries_area
	Geometry: Polygon
	Feature Count: 27458
	Extent: (-180.000000, -90.000000) - (180.000000, 83.627419)
	Layer SRS WKT:
	(unknown)
	FAC_ID: Integer (5.0)
	TILE: Integer (3.0)
	ARCLIST: String (254.0)
	NAM: String (77.0)
	PERIMETER: Real (22.17)
	POLYGONCOU: Integer (6.0)
	NA2DESC: String (45.0)

Map File Example::

	LAYER
  		NAME my_shapefile
  		TYPE POLYGON
  		DATA countries_area
  		STATUS OFF
  		CLASS
    		NAME "Countries"
    		OUTLINECOLOR 0 0 0
  		END
	END