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Fortran in Practice

This section describes the steps required to turn a Fortran program from a piece of text into executable form. The main operation is that of translating the original Fortran source code into the appropriate machine code. On a typical Fortran system this is carried out in two separate stages. This section explains how this works in more detail.

These descriptions differ from those in the rest of the book in two ways. Firstly, it is not essential to understand how a Fortran system works in order to use it, just as you do not have to know how an internal combustion engine works in order to drive a car. But, in both cases, those who have some basic understanding of the way in which the machine works find it easier to get the best results. This is especially true when things start to go wrong - and most people find that things go wrong all too easily when they start to use a new programming language.

Secondly the contents of this section are much more system-dependent than all the others in the book. The Fortran Standard only specifies what a Fortran program should do when it is executed, it has nothing directly to say about the translation process. In practice, however, nearly all Fortran systems work in much the same way, so there should not be too many differences between the ``typical" system described here and the one that you are actually using. Regrettably the underlying similarities are sometimes obscured by differences in the terminology that different manufacturers use.





Mario Storti
Wed Nov 4 19:32:56 ART 1998