1.2. File scopes

After this brief excursion into the history of file systems, consider the possible areas of their application. First of all, of course, files are used to store text data: documents, program texts, etc. Such files are usually generated and modified using various text editors. The structure of text files is usually very simple: it is either a sequence of records containing lines of text or a sequence of bytes, among which there are special characters (for example, the characters of the end of a line).

Files with the programs are used as input texts of the compilers, which in turn form files containing object modules. From the point of view of the file system, object files also have a very simple structure - a sequence of records or bytes. The programming system imposes on this structure a more complex and specific for this system structure of the object module. We emphasize that the logical structure of the object module is unknown to the file system; this structure is supported by the programming system programs.

The situation is similar with files formed by link editors and containing images of executed programs. The logical structure of such files remains known only to the link editor and the loader — the operating system program. Approximately the same situation with files containing graphic and audio information.

In a word, file systems usually provide storage of poorly structured information, leaving further structuring to application programs. In the above cases of using files, it is even good, because when developing any new application system, relying on simple, standard and relatively cheap file system tools, you can implement those storage structures that most naturally correspond to the specifics of a given application area.