On Re-inventing Wheels

It is well known that one should not waste time "re-inventing the wheel". In Engineering, this means not redesigning something one has already got a perfectly satisfactory design for. In Software Engineering, it means not rewriting software to perform operations that one has previously written (and tested!) software for.

In the case of the C language there are a range of things that programmers very frequently wish to do, which are so common that standard software for the purpose is actually distributed along with every C compiler. This software is called the C Standard Library. You are more or less guaranteed that every C compiler will come with an implementation of the Standard Library. It is important to be aware at least of the existence of the Standard Library, and to have some outline idea of the software contained in the Library. In this way you can avoid unnecessarily writing and testing software which is already effectively available, in a well tested form, for free.

The recommended compiler for the current course is DJGPP, which is a port (version) of the GNU C Compiler for the PC platform. Detailed information on the C Standard Library (Version 1.12) provided with this compiler is available in the Web-based documentation. You should consult this whenever you need details of the full range of functionality of the Standard Library.

On the other hand, this essay is intended only to provide an introduction to a very small subset of the Standard Library, and is not a substitute for full DJGPP documentation.