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VICAR Directory Structure

The directory structure of VICAR is now quite different from the old directory structure. Directories have been generally rearranged to provide a more hierarchical and consistent directory tree. The directory tree is shown diagramatically in Figure , on the next page.

It is important to note that while directories have moved all over the place, the VMS logical names that point to the directories are in general the same (there have been a few deletions and a lot of additions, but most of the useful old ones are still there). So, as long as you use logical names (such as ``v2$source'' for the RTL source), like you are supposed to, you won't notice the directory changes. Under Unix, environment variables will point at the various directories instead of logical names.

So, although the directory tree changes will not affect most users, they are mentioned below for completeness.

Every subsystem within VICAR is now isolated in its own directory tree. For example, all the RTL source and includes are under the ``rtl'' directory. All source, includes, fonts, and programs for the VRDI are under the ``vrdi'' directory. All source, includes, subroutines, and executables for class 2 applications are under the ``p2'' directory. This makes it clearer where a module stands in the VICAR hierarchy.

The new directory structure is designed to allow several different computer systems to use the same copy of VICAR. All machine-specific object code and executables are isolated in directories bearing the name of the machine they belong to. For example, the class 2 application executables (r2lib) for a Sun-4 system reside in p2/lib/sun-4, while for an HP 700 they would be in p2/lib/hp-700. The different machines access the same directory tree using NFS (Network File System), but still have machine-specific compiled code where needed. These machine-specific directories are represented by the ``targets...'' boxes on the directory chart.

The directory tree has been renamed, as shown in the diagram. The top level used to be called ``mipl'' or some derivative (such as ``mipl060''). Now, it is called ``vicar''.

Everything that is not directly a part of VICAR has been removed from the VICAR source tree. The old Development system directory tree contained many files that had nothing to do with the running VICAR system, such as CMS libraries, old build logs, delivery audit trails, and test images. These have all been eliminated from the VICAR tree, and have their own directories (actually most of them are still in the old ``mipl'' directory tree).

The fetch and build procedures have been cleaned up and are now entirely separate operations. The fetch routine gets everything from the code management system (CMS) at once, and then the build routine compiles and links everything as a separate operation. This makes building VICAR at foreign sites much easier. The same philosophy holds under both VMS and Unix - fill all the directories at once, then build everything. The fetch files are all in the utilities directory, while the build files are in the top-level directories of the subsystems they build.

There are two directories that are created entirely during the build process. They fall outside the subsystem hierarchy, since they contain files from many different places in the directory tree. These files are grouped into these directories for convenience. Since they are created during the build, and contain no source code, being outside the hierarchy does not present a significant problem. The first is the ``olb'' directory, which contains all the object (link) libraries in the VICAR system. The second is the ``lib'' directory, which contains miscellaneous executables and TAE PDFs from various parts of the VICAR system.

rgd059@ipl.jpl.nasa.gov