Shapefile C Library package provides the ability to write simple C programs for reading, writing and updating (to a limited extent) ESRI Shapefiles, and the associated attribute file (.dbf).
What is a Shapefile?
If you don't know, you probably don't need this library. The Shapefile format is a working and interchange format promulagated by ESRI for simple vector data with attributes.
An excellent white paper on the shapefile format is available from ESRI, but it is .pdf format, so you will need Adobe Acrobat to browse it.
The file format actually consists of three files.
XXX.shp - holds the actual vertices.
XXX.shx - hold index data pointing to the structures in the .shp file.
XXX.dbf - holds the attributes in xBase (dBase) format.
Limitations:
· You can't modify the vertices of existing structures (though you can update the attributes of existing structures, and create new structures).
· Not written in such a way as to be particularly fast. This is particularly true of the 1.2 API. For applications more concerned with speed it may be worth using the V1.1 API.
· Doesn't set the last access time properly in the .dbf files.
· There is no way to synchronize information to the file except to close it.
· Poor error checking and reporting.
· Not professionally supported (well it can be, if you want to pay).
· Some aspects of xBase files not supported, though I believe they are not used by ESRI.
· The application must keep the .dbf file in sync with the .shp/.shx files through appropriate use of the DBF and SHP APIs.
· No support for the undocumented .sbn/.sbx spatial index files.
Product's homepage
Find us on Google+
