compile C program under mac classic

I've a C program which need to be compiles and test with a Mac classic. specification of this program is as following: - already runs under Linux, Mac OS-X, and Windows XP. - about 800 lines - no graphical input/output (runs from the command line) - input from the command line (2 to 4 parameters for a total of 6 different messages) - output are saved in files. - Read/write some datas from a mysql remote database.