GETUID(2)
NAME
getuid, geteuid − get user identity
USAGE
uid = getuid() int uid;
euid = geteuid() int euid;
DESCRIPTION
Getuid returns the real user ID of the current process, geteuid the effective user ID.
The real user ID (uid) identifies the account that is logged in. The effective user ID (euid) gives the process additional permissions during execution of “set-user-ID” mode processes, which use getuid to determine the real user-ID of the process which invoked them.
RETURN VALUE
If successful, these calls return the real user ID and effective user ID, respectively, of the current process.