There are some things to watch out for when doing program listings. Let's say that we want to put the following fragment of code into DocBook:

#include <stdio.h>
int main ()
{
        int count = 3;
        while (count--)
                printf ("Count is now %d\n", count);
}

    

The problem is that <stdio.h> will be interpreted as an SGML tag. For this small fragment, it is easy to replace the <-signs with &lt;, but for larger code fragments there could easily be missed SGML entities.

A slightly easier way is to enclose it in a CDATA tag (i.e. literal text), like this:

<programlisting><![CDATA[
…
]]></programlisting>
   

The next thing to bear in mind is that Tab characters will not be expanded to spaces, so you will need to do all the indenting with spaces.

	Warning
	There is currently a bug in xmltex that causes incorrect output for “--” (i.e. two dashes). Grab the latest PassiveTeX for an xmltex.tex and PassiveTeX distribution with this fixed.

Of course, Appendix A, DocBook XML source of this book needs to include quite a lot of source code (XML rather than C), and the approach I have taken in order to be sure that I haven't missed anything is to have the Makefile run sed on the original source, and just include the result as an entity. Take a look at Appendix A, DocBook XML source to see how that's done.