ar keys archive [obj_ files]The most important keys are r to replace or add modules to the archive and t to display a table of contents. The archive is a name composed of lib name.a. For example the command sequence:
cc -c func1.ccompiles func1.c, func2.c, func3.c and adds the object files into the libmy.a.cc -c func2.c
cc -c func3.c
ar r libmy.a func1.o func2.o func3.o