# comp.lang.c Frequently Asked Questions

This collection of hypertext pages is Copyright 1995 by Steve Summit. Content from the book ``C Programming FAQs: Frequently Asked Questions'' (Addison-Wesley, 1995, ISBN 0-201-84519-9) is made available here by permission of the author and the publisher as a service to the community. It is intended to complement the use of the published text and is protected by international copyright laws. The content is made available here and may be accessed freely for personal use but may not be published or retransmitted without written permission.

This page is the top of an HTML version of the Usenet comp.lang.c Frequently Asked Questions (FAQ) list. An FAQ list is a collection of questions commonly asked on Usenet, together with presumably definitive answers, provided in an attempt to keep repeated questions on the newsgroup down to a low background drone so that discussion can move on to more interesting matters. Since they distill knowledge gleaned from many sources and answer questions which are demonstrably Frequent, FAQ lists serve as useful references outside of their originating Usenet newsgroups. This list is, I dare to claim, no exception, and the HTML version you're looking at now, as well as other versions referenced just below, are intended to be useful to C programmers everywhere.

Several other versions of this FAQ list are available, including a book-length version published by Addison-Wesley. (The book, though longer, also has a few more errors; I've prepared an errata list.) See also question 20.40.

Like so many web pages, this is very much a ``work in progress.'' I would, of course, like it if it were perfect, but it's been two years or so since I first started talking about putting this thing on the web, and if I were to wait until all the glitches were worked out, you might never see it. Each page includes a ``mail feedback'' button, so you can help me debug it. (At first, you don't have to worry about reporting minor formatting hiccups; many of these result from lingering imperfections in the programs that generate these pages, or from the fact that I have not exhaustively researched how various browsers implement the HTML tags I'm using, or from the fact that I haven't gone the last yard in trying to rig up HTML that looks good in spite of the fact that HTML doesn't have everything you need to make things look good.)

These pages are synchronized with the posted Usenet version and the Addison-Wesley book version. Since not all questions appear in all versions, the question numbers are not always contiguous.

[Note to web authors, catalogers, and bookmarkers: the URL <http://www.eskimo.com/~scs/C-faq/top.html> is the right way to link to these pages. All other URL's implementing this collection are subject to change.]

You can browse these pages in at least three ways. The table of contents below is of the list's major sections; these links lead to sub-lists of the questions for those sections. The ``all questions'' link leads to a list of all the questions; each question is (obviously) linked to its answer. Finally, the ``read sequentially'' link leads to the first question; you can then follow the ``next'' link at the bottom of each question's page to read through all of the questions and answers sequentially.

Steve Summit
scs@eskimo.com

1. Declarations and Initializations

2. Structures, Unions, and Enumerations

3. Expressions

4. Pointers

5. Null Pointers

6. Arrays and Pointers

7. Memory Allocation

8. Characters and Strings

9. Boolean Expressions and Variables

10. C Preprocessor

11. ANSI/ISO Standard C

12. Stdio

13. Library Functions

14. Floating Point

15. Variable-Length Argument Lists

16. Strange Problems

17. Style

18. Tools and Resources

19. System Dependencies

20. Miscellaneous

Bibliography

Acknowledgements

All Questions

Read Sequentially