I found this book frustrating. Parts of it are quite good, while others are too skimpy to be useful.

The first section, “X Window System Programming 101,” offers a whirlwind tour of low-level Xlib programming, with short chapters on window creation, event handling, image drawing, bitmaps, and color handling, followed by discussions of the X resource manager and an introduction to programming with X toolkits. Although they take up 180 pages, I found these chapters adequate as a refresher for someone who had not done any X programming for a while (like me), but much too sketchy for an introduction to X programming, and too basic for an experienced programmer. The authors seem to agree, since they refer the reader to their other, more basic books in places where the exposition is particularly thin.

The second part of the book moves to the more advanced area of program-to-program communication. The authors start by developing a small software toolkit to be used in the rest of the book. Subsequent chapters extend that toolkit to handle basic cutting and pasting, sending events from one application to another, selection of text and non-text data, and interaction with window and session managers.

The third part contains two chapters on the exotic topic of using multiple displays from the same program. (It is not that exotic for programmers of multi-user simulation games.) The book finishes with looks at two common X extensions, non-rectangular windows (“shape”) and the X Image extension, and a short chapter on changes in X11 Release 6.

The authors clearly have tremendous X experience and expertise, which come through in many practical notes explaining why things that one might expect to work do not, and some suggestions for defensive programming to make applications work on different, slightly incompatible platforms. Nonetheless, the book feels basically unsatisfactory, like a grab bag of pieces that did not fit into their other books. Developing a small toolkit from scratch is an interesting exercise and, as the authors point out, it is interesting to see that one can write useful applications based on a small toolkit, but it is no longer very realistic. X applications now all use one of the standard toolkits, and real programming is all done in terms of those toolkits.

The book comes with a CD-ROM that contains all of the source code in the book along with the complete publicly available source of X11R6. Oddly, although I had no trouble reading the X11R6 source, I was unable to read the book’s source code. Unlike the source in most competing books, this code is not available online (“Don’t bother asking us if it is” says a note in the back), so I was not able to test it.