Chances are you’ll never have to deal with Tk widgets at the C level, because the existing toolkit is so rich, and because you can quickly and efficiently build new mega-widgets using the powerful techniques described in Chapter 14. But there may come a time when you have to leave the cozy world of Perl and delve into C, perhaps because of efficiency considerations, or a missing system call, or maybe because you have an existing Tcl/Tk C widget you’d like to port to Perl/Tk.
In this chapter, we’ll closely examine a simple (but real) C widget and see how to package, build, test, and install it. This is a Unix-centric chapter, because we have no Win32 development environment. But the porting essentials are still relevant.