GETPID(2) BSD Programmer's Manual GETPID(2)
getpid, getppid - get parent or calling process identification
#include <sys/types.h> #include <unistd.h> pid_t getpid(void); pid_t getppid(void);
getpid() returns the process ID of the calling process. Though the ID is guaranteed to be unique, it should NOT be used for constructing temporary file names; see mkstemp(3) instead. getppid() returns the process ID of the parent of the calling process.
The getpid() and getppid() functions are always successful, and no return value is reserved to indicate an error.
gethostid(3)
getpid() and getppid() conform to IEEE Std 1003.1-1988 ("POSIX.1"). MirBSD #10-current June 4, 1993 1