Solutions for "The C Programming Language", 2nd Edition, Kernighan and Ritchie. Lin Ke-Fong (another_lin@yahoo.com) I read the book a while ago and did most of the exercises, this was a copy from my university's library. When I finally bought it, I figure out it would be fun to do them all seriously. The solutions are written trying to use the same style as the book. They follow chapter ordering and try not to use features described later. I have developed them using Linux and gcc but they have also been tested on Mac OS X and Windows using XCode and Visual C++. Exercises are command line oriented, taking inputs from file redirection most of the time. When possible, you should compile in strict ANSI mode, with all warnings on and maximum optimization. Warnings even if sometimes more annoying than really useful, may still point genuine problems. A lot of exercises are about writing simplified or even full versions of C standard library functions. Hence there can be clashes at compilation or linking. Compiling in strict ANSI mode will avoid most problems, even if the compiler or linker may still continue to complain a bit. On BSD systems and Mac OS X (Darwin is a BSD), you will also need to define the _ANSI_SOURCE macro. Moreover, there can still be issues with intrinsic (built-in) functions: warnings for gcc but you will have to switch them off with Visual C++. Enabling optimizations permit further error checking as the compiler does a more detailed dataflow analysis. However, floating-point computations (exercise 2-1) may end up wrong depending of the compiler and processor. Here are some examples of compilation commands: GNU C: gcc -ansi -Wall -pedantic -O3 GNU C (BSD or Mac OS X): gcc -ansi -Wall -pedantic -D_ANSI_SOURCE -O3 Intel C Compiler: icc -strict-ansi -w2 -fast Microsoft Visual C (no intrinsic): cl /Ox /Oi- /Za /Wall See compilers' manuals for full details. Exercises of chapter 8 won't compile at all with Visual C++. However, you can make the first four of them work by commenting the unistd.h includes. You may also want to check "The C Answer Book" by Clovis L. Tondo and Scott E. Gimpel. Or the website maintained by Richard Heathfield: http://users.powernet.co.uk/eton/kandr2/ To end up, I wish to thank all my friends and relatives.