Storing, Retrieving, and Editing Programs

The purpose of this document is to explain how to maintain programs and other small files for use on NCAR's batch computers. Annotated examples are used to show how most common file operations may be performed. For clarity, the examples are often idealized to illustrate particular methods or concepts, but every effort has been made to ensure that the examples are correct. More complete information about the tools and methods described in this guide may be found in the reference manuals listed at the end of this chapter. For backup and restoration procedures and simple operations like copying, it does not matter what kind of information is actually stored in a collection of files. What is important for these kinds of operations is an understanding of the file system and some of the characteristics of the physical media on which information must be stored. When dealing with other operations on small files, it is convenient to classify them as either text files or object files. Text files contain information in character form; examples are program source files and some small data files. Editing tools are needed in order to modify text files. Object files contain some form of the output from compilers and assemblers; examples are absolute binary programs and binary libraries. Object files require a different set of operations than text files, supported by a different set of tools. The tools available for small file management can thus be characterized by their purpose: backup, editing, or object file management. These three topics are the basis for the organization of this user guide. Such an organization will aid the user in understanding what is possible and what is difficult on both machines, so that an intelligent choice can be made about which machine is best to use for a given task.