osx man page for getpid

GETPID(2)						      BSD System Calls Manual							 GETPID(2)

NAME
     getpid, getppid -- get parent or calling process identification

SYNOPSIS
     #include <unistd.h>

     pid_t
     getpid(void);

     pid_t
     getppid(void);

DESCRIPTION
     Getpid() returns the process ID of the calling process.  The ID is guaranteed to be unique and is useful for constructing temporary file
     names.

     Getppid() returns the process ID of the parent of the calling process.

ERRORS
     The getpid() and getppid() functions are always successful, and no return value is reserved to indicate an error.

LEGACY SYNOPSIS
     #include <sys/types.h>
     #include <unistd.h>

     The include file <sys/types.h> is necessary.

SEE ALSO
     gethostid(2), compat(5)

STANDARDS
     Getpid() and getppid() conform to IEEE Std 1003.1-1988 (``POSIX.1'').

4th Berkeley Distribution					   June 4, 1993 					 4th Berkeley Distribution