C programming notes - School of Physics

C programming notes
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know, but that is another story...
Some problems with C
The language was designed with writing operating systems in mind, and so it was not purpose-built for numerical
work.
There is no support for complex numbers (actually, as of the C-99 standard, there is!).
Handling multi-dimensional arrays, understanding pointers, and string manipulation are difficult when you first
encounter them.
It is easy to write completely opaque code in C.
You have to explicitly declare every variable that you use. This is actually not a problem at all! It is a feature.
It is possible to bypass many of the protective features of the language, and get yourself into trouble
(alternatively, this can be seen as an advantage, since the language imposes few limitations on what you can do).
The ANSI C standard leaves a lot of details undefined. This makes C non-portable between different operating
systems, compilers, and computer hardware. Java is better in this respect.
It is not easy to write large bug-free programs in C. Java is often a better choice.
A brief history of C
C evolved from a language called B, written by Ken Thompson at Bell Labs in 1970. Ken used B to write one of the
first implementations of UNIX. B in turn was a decendant of the language BCPL (developed at Cambridge (UK) in
1967), with most of its instructions removed.
In fact, so many instructions were removed in going from BCPL to B, that Dennis Ritchie of Bell Labs put some back
in (in 1972), and called the language C.
The famous book The C Programming Language was written by Kernighan and Ritchie in 1978, and has remained the
definitive reference book on C.
The original C was still too limiting, and not standardized, and so in 1983 an ANSI committee was established to
formalise the language definition.
By 1993 the ANSI standard became well accepted and almost universally supported by compilers. The GNU C
compiler, gcc, has become, in many ways, the standard implementation of C.
What about C++ and C#?
C++ is a superset of C, incorporating many object-oriented programming ideas. However, it is not particularly widely
used. Java is a better choice in most cases.
C# is a Java-like language developed by Microsoft. Enough said.
Interesting books
Numerical Analysis by Burden and Faires.
A New Kind of Science by Wolfram.
Numerical Recipies in C
Other on-line resources
For coverage of typical problems encountered with C, have a look at the Comp.lang.c FAQ.
For a rather good tutorial introduction to C, check out this document by Gordon Dodrill.
The simplest possible C program
Here it is.
Hello world