Portable Real-Time Applications

“The purpose of computing is insight, not numbers.” --Richard Hamming, 1915-1998
Portability Considerations

In the sidebar “How to Compile and Run Listing 4”, you can see how to compile the stage 3 program on different platforms and how to start the whole application as a UNIX pipe. You might be surprised to find that the compiler gcc can be used even with the Win32 operating systems. How is this possible? The gcc for Win32 is part of a UNIX-compatible environment called the Cygwin Toolset (see Resources). It allows you to work with gcc and its friends on any Win32 operating system just as if it were a well-behaved UNIX system. Many GNU packages run out of the box with it. If you want to use the multimedia functions of Win32 (along with DirectX access) or the POSIX thread library, you must get and install them separately (see Resources). Since I started working on Win32, it became more and more important to adhere to the POSIX system calls, written down in the XPG4 set of standards. Doing so has become a rewarding habit, because it is the cornerstone of portability in the UNIX world.

What pleased me most was the possibility of installing gcc from the Cygwin Toolset as a cross compiler on my Linux 2.2 system. Now I can write and debug my software with Linux, no matter where it is supposed to run later. In the end, I compile it with the cross compiler and get a debugged Win32 executable. What an achievement! If you also would enjoy working this way, follow Mumit Khan's recipe for cooking a cross compiler (see Resources).


Jürgen Kahrs (Juergen.Kahrs@t-online.de) is a development engineer at STN Atlas Elektronik in Bremen, Germany. There, he uses Linux for generating sound in educational simulators. He likes old-fashioned tools such as GNU AWK and Tcl/Tk. He also did the initial work for integrating TCP/IP support into gawk.