Information exchange between programs

[pokevitek]

Hi, when program is executed, it should get its own virtual adres space from OS. This way progam cannot rewrite any other programs, or OS components. But, if it has its own adres space translated to physical memory by MMU, how can program communicate with other programs? And how can program call OS functions? I know that basic variable exchange between functions is done by stack push and pop operations, but how is system function(routines) called, and how can program exchange variables with other ones?

[WingedPanther]

It depends on the OS. POSIX and Windows API both provide mechanisms for inter-app communications.