You can often use the open-source GNU autoconf(1) we surveyed in Chapter15 to handle portability issues, do system-configuration probes, and tailor your makefiles. People building from sources today expect to be able to type configure; make; make install and get a clean build. There is a good tutorial on these tools. Even if you're distributing in binary, the autoconf(1) tools can help automate away the problem of conditionalizing your code for different platforms.

Other tools that address this problem; two of the better known are the Imake(1) tool associated with the X windowing system and the Configure tool built by Larry Wall (later the inventor of Perl) and adapted for many different projects. All are at least as complicated as the autoconf suite, and no longer as often used. They don't cover as wide a range of target systems.