Ben Klemens - 21st Century C

Is it really punk rock
Like the party line?

Wilco ``Too far apart''

Q: How is this C book different from all others?

A: C textbooks are a pretty uniform bunch (Ive read a lot of them, including ). Most were written before the C99 standard simplified many aspects of usage, and you can tell that some of those now in their N th edition just pasted in a few notes about updates rather than really rethinking how to use the language. They all mention that there might be libraries that you could use in writing your own code, but they predate the installation tools and ecosystem we have now that make using those libraries reliable and reasonably portable. Those textbooks are still valid and still have value, but modern C code just doesnt look like the code in those textbooks.

This book picks up where they left off, reconsidering the language and the ecosystem in which it lives. The storyline here is about using libraries that provide linked lists and XML parsers, not writing new ones from stratch. It is about writing code that is readable and function interfaces that are user-friendly.

Q: Who is this book for? Do I need to be a coding guru?

A: You have experience coding in any language, maybe Java or a scripting language like Perl. I dont have to sell you on why your code shouldnt just be one long routine with no subfunctions.

You have some knowledge of C, but dont worry if you dont know it too wellas Ill detail, theres a lot youre better off never learning. If you are a blank slate with respect to C syntax, it really is an aggressively simple language, and your search engine will point you to dozens of C tutorials online; if you have experience with another language, you should be able to get the basics in an hour or two.

I might as well point out to you that I have also written a textbook on statistical and scientific computing, Modeling with Data . Along with lots of details of dealing with numeric data and using statistical models for describing data, it has a standalone tutorial on C, which I naturally think overcomes many of the failings of older C tutorials.

Q: Im an application programmer, not a kernel hacker. Why should I use C instead of a quick-to-write scripting language like Python?

A: If you are an applications programmer, this book is for you. I read people asserting that C is a systems language, which impresses me as so un-punkwho are they to tell us what were allowed to write?

Statements in the way of our language is almost as fast as C, but is easier to write are so common that they are almost clich. Well, C is definitely as fast as C, and the purpose of this book is to show you that C is easier to write than the textbooks from decades passed imply that it is. You dont have to call malloc and get elbow-deep in memory management half as often as the systems programmers of the 1990s did, we have facilities for easier string handling, and even the core syntax has evolved to make for more legible code.

I started writing C in earnest because I had to speed up a simulation in a scripting language, R. Like so many other scripting languages, R has a C interface and encourages the user to make use of it any time the host language is too slow. Eventually I had so many functions jumping out from the R script to C code that I just dropped the host language entirely. Next thing you know, Im writing a book on modern C technique.

Q: Its nice that application programmers coming from scripting languages will like this book, but I am a kernel hacker. I taught myself C in fifth grade and sometimes have dreams that correctly compile. What new material can there be for me?