#include <unistd.h>
pid_t fork(void);
fork creates a child process that differs from the parent
process only in its PID and PPID, and in the fact that
resource utilizations are set to 0. File locks and pend
ing signals are not inherited.
Under Linux, fork is implemented using copy-on-write
pages, so the only penalty incurred by fork is the time
and memory required to duplicate the parent's page tables,
and to create a unique task structure for the child.
As always, I hope that helped!
Disclaimer:
Beware: Studies have shown that research causes cancer in lab rats.