3. Some additional portability comments

Try to avoid :

• macros with variable number of arguments (gcc specific)
• iusing ' in macros (gcc doesn't like it) (i.e. no #error Didn't work !)
• inlining functions (gcc specific) (if you do, try to provide a fallback .c file)
• avoid doing things like (void *) struct->ptr = my_pretty_function; and instead declare arguments like : struct->ptr = ((int *)(int,int,int)) my_pretty_function;
• doing arithmetic on (void *) like in void *bla;*(bla+10)=blubb;. This is GCC specific and very confusing.
• If you write shell scripts, always use /bin/sh
• As most Linux-systems have /bin/sh symlinked to bash this won't help that much. I suggest that if you want to write/modify scripts you install at least one other Bourne-style shell and test your code with it.
• Never make ANY assumptions about the size of datatypes! If your code depends on a datatype being of a certain size, use the [us]int* datatypes.
• Do NOT use uchar, ushort, uint or ulong! Those are very non-standard datatypes. Either use one of the GGI datatypes or unsigned <type>.
• Don't use gcc specific stuff unless you're writing code that is expected to be compiled with gcc only (ie. Linux kernel code)