Compilation Instructions

Firstly, we need to be able to compile tortoise1. This is a simple UNIX program which uses Xlib, so to compile it we need something like:

cc -o tortoise1 tortoise1.c -I/usr/X11R6/include -lX11 -L/usr/X11R6/lib -lm

To break this down into its constituent parts:

• cc is the command to invoke the C compiler and linker.
• -o tortoise1 says that the executable program should be called tortoise1.
• tortoise1.c tells the compiler where to find the source code for the program.
• The source code needs to access the header files for Xlib, so we tell the compiler where they are with -I/usr/X11R6/include. Your system might have these header files in a different place.
• The program needs to use the shared library which contains the implementations of the Xlib functions that the program uses. This is the library libX11; we tell the linker about it with -lX11
• We may also need to tell the linker where to look for this libX11 library, which is -L/usr/X11R6/lib on my system.
• The program also needs the system math library libm (for sin and cos) , so we have -lm

The example above is for a RedHat6.0 GNU/Linux system; for other systems you may well find that the Xlib headers and libraries are accessible in standard directories like /usr/include and /usr/lib - in which case, a simple

cc -o tortoise1 tortoise1.c -lX11 -lm

will suffice

If this doesn't work, you can try one of the following:

• Solaris 2.x:

  cc -o tortoise1 tortoise1.c -I/usr/openwin/include -lX11 -L/usr/openwin/lib -lm

• HP-UX 10.20:

  cc -o tortoise1 tortoise1.c -I/usr/include/X11R6 -lX11 -L/usr/lib/X11R6 -lm

• AIX 4.2:

  cc -o tortoise1 tortoise1.c -I/usr/lpp/X11/include -lX11 -L/usr/lpp/X11/lib/R6 -lm

Once we add Guile functionality to the program, we also need to tell the compiler and linker how to get access to the relevant Guile headers and libraries.

Fortunately, figuring out how to do this is very easy, because Guile comes with a utility to make it easy.

• To figure out what options need to be added in the compilation phase, just run guile-config compile. On my system, this gave -I/usr/include (which is an include directory that is automatically searched by the compiler anyway).
• To figure out what options need to be added in the link phase, just run guile-config link. (On my system, this yielded -L/usr/lib -lguile -ldl -lreadline -ltermcap -lm)