getuid(2)
NAME
getuid, geteuid − get user identity
SYNTAX
uid = getuid()
int uid;
euid = geteuid()
int euid;
DESCRIPTION
The getuid system call returns the real user ID of the current process, geteuid the effective user ID.
The real user ID identifies the person who is logged in. The effective user ID 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.
ENVIRONMENT
Differs from the System V definition in that the return values are ints instead of unsigned shorts.