ArcView Shapefile

ArcView Shapefile files are supported by the GDB library for import and export. The Shapefile format contains vector and attribute information. Typically, data sets include four files with a common basename and the extensions .shp, .shx, .dbf and .prj. When you import a shapefile, the .prj file is used to determine the georeferencing of the data. When you export to a shapefile, a .prj file is created and which stores the georeferencing, when possible; otherwise, it is written to a .pox file.

The polygon and arc layer types contain what ESRI calls multipart shapes. For instance, a multipart polygon would be the outer boundary and all the interior holes in the polygon. The multiple parts are maintained using the RingStart mechanism.

POINTM, ARCM, POLYGONM, and MULTIPOINTM shapes contain an additional "measurement" value at each vertex. These measurement values are ignored by GDB and lost in the conversion process.

POINTZ, ARCZ, POLYGONZ, and MULTIPOINTZ are three 3-D shapes, whereas the POINT, ARC, POLYGON and MULTIPOINT types are 2-D (Z is always zero). The Z and M shape types are new in ArcView 3.x.

The MULTIPATCH shape is a special complex type for representing TINs. The tesselation information inherent in the multipatch is lost by GDB; however, all the data points are preserved on read.

The Shapefile attributes are stored in an xBase (.dbf) file, which is also supported as a standalone GDB format. For more information about the .dbf translator, see xBase (DBF).

Shapefiles are produced by ArcView, and Arc/Info. In Arc/Info, use the ARCSHAPE command to export a coverage to a shapefile, or the SHAPEARC command to import a shapefile and build a coverage.

Export of ArcView Shapefiles is supported. These files are exported with a type of "SHP".

Only one vector layer can be exported to a single shapefile.

The output file name for the shapefile to be created should have an extension of .shp or .shx. When you export data, three files are created with the same basename, and the extensions .shp, .shx, and .dbf. Together, these make a data set with attributes.

Shapefiles do not have georeferencing nor are any other data types supported, other than vector layers. Georeferencing information usable by GDB software is written to a .pox file, but this format is not supported by ArcView, or Arc/Info.

You can use the option value to select a layer type to assign to the shapefile you create. If no options are specified, the system selects either MULTIPOINT, ARC, or POLYGON depending on the nature of the first shape written to the file, or the LAYER_TYPE metadata.

 option = "POINT"              | each shape is a single point
 option = "ARC"                | each shape is a set of poly lines
 option = "MULTIPOINT"         | each shape is a set of points
 option = "POLYGON"            | each shape is a set of closed arcs
 option = "POINTZ"             | each shape is a single 3-D point
 option = "ARCZ"               | each shape is set of 3-D polylines
 option = "MULTIPOINTZ"        | each shape is a set of 3-D points
 option = "POLYGONZ"           | each shape is a set of 3-D closed arcs