36.6 Process, Group, and User IDs
— Built-in Function: pgid = 
getpgrp ()
Return the process group id of the current process. 
— Built-in Function: pid = 
getpid ()
Return the process id of the current process. 
— Built-in Function: pid = 
getppid ()
Return the process id of the parent process. 
— Built-in Function: euid = 
geteuid ()
Return the effective user id of the current process. 
— Built-in Function: uid = 
getuid ()
Return the real user id of the current process. 
— Built-in Function: egid = 
getegid ()
Return the effective group id of the current process. 
— Built-in Function: gid = 
getgid ()
Return the real group id of the current process.