[This is the introductory text for the plain-text version of the C FAQ list, as posted to its original home, namely the Usenet newsgroup comp.lang.c.]

Certain topics come up again and again on this newsgroup. They are good questions, and the answers may not be immediately obvious, but each time they recur, much net bandwidth and reader time is wasted on repetitive responses, and on tedious corrections to any incorrect answers which may unfortunately be posted. This article, which is posted monthly, attempts to answer these common questions definitively and succinctly, so that net discussion can move on to more constructive topics without continual regression to first principles.

No mere newsgroup article can substitute for thoughtful perusal of a full-length tutorial or language reference manual. Anyone interested enough in C to be following this newsgroup should also be interested enough to read and study one or more such manuals, preferably several times. Some C books and compiler manuals are unfortunately inadequate; a few even perpetuate some of the myths which this article attempts to refute. Several noteworthy books on C are listed in this article's bibliography; see also questions 18.19 and 18.10. Many of the questions and answers are cross-referenced to these books, for further study by the interested and dedicated reader.

If you have a question about C which is not answered in this article, you might first try to answer it by checking a few of the referenced books, or one of the expanded versions mentioned below, before posing your question to the net at large. There are many people on the net who are happy to answer questions, but the volume of repetitive answers posted to one question, as well as the growing number of questions as the net attracts more readers, can become oppressive. If you have questions or comments prompted by this article, please reply by mail rather than following up--this article is meant to decrease net traffic, not increase it.

Besides listing frequently-asked questions, this article also summarizes frequently-posted answers. Even if you know all the answers, it's worth skimming through this list once in a while, so that when you see one of its questions unwittingly posted, you won't have to waste time answering. (However, this is a large and heavy document, so don't assume that everyone on the net has managed to read all of it in detail, and please don't roll it up and thwack people over the head with it just because they missed their answer in it.)

This article was last modified on July 3, 2004, and its travels may have taken it far from its original home on Usenet. It may, however, be out-of-date, particularly if you are looking at a printed copy or one retrieved from a tertiary archive site or CD-ROM. You should be able to obtain the most up-to-date copy at http://www.eskimo.com/~scs/C-faq/top.html or http://www.faqs.org/faqs/, or via ftp from ftp://rtfm.mit.edu/. (See also question 20.40.) Since this list is modified from time to time, its question numbers may not match those in older or newer copies which are in circulation, so be careful when referring to FAQ list entries by number alone. (Also, this article was produced for free redistribution. You should not need to pay anyone for a copy of it.)

Several other versions of this document are available. Posted along with it are an abridged version and (when there are changes) a list of differences with respect to the previous version. A hypertext version is available on the web at the aforementioned URL. For those who might prefer a bound, hardcopy version, a book-length version has been published by Addison-Wesley (ISBN 0-201-84519-9). The hypertext and book versions include additional questions and more detailed answers, so you might want to check one of them if you still have questions after reading this posted list.

This article can always be improved. Your input is welcome. Send your comments to scs@eskimo.com .

(The question numbers within each section are not always continuous, because they are aligned with the aforementioned book-length version, which contains even more questions.)