The common file has evolved over the years to meet the changing needs by applications such as CFD. The current version is version 3. The following summarizes the changes to the common file for the each new version.
Initial release of the common file with the built in limits shown in the section "Default Library Values and Limits."
The second release increased the limits on the number of nodes and the number of variables. This caused a minor change in how some of the internal pointers were stored. For files created with limits within version 1 there was no change in structure. Thus they could be read by version 1 libraries.
Version 3 represents a major change in the file structure based on the
CGNS (CFD General Notation System)
data structure.
The CGNS project was sponsored by NASA for Boeing to
develop the next generation common file structure.
The new structure removes the current common file limits, adds support
for more data types and includes both a C and Fortran interface.
The result is the ADF (Advanced Database Format) library which is written
in C and supersedes the Boeing common file library.
In order to maintain compatibility with old common files and
provide support for the new format the ADF core has been layered under
the common file interface creating version 3.
Several new functions have been added as well as many limits being
removed with no changes to the user interface for existing functions.
Note that version 3 files cannot be read with version 1 or 2 libraries.
Last updated 16 Mar 1999