sys-getuid(2) - Unix First Edition Manual Page
11/3/71SYS_GETUID (II)

NAME getuid -- get user identification
SYNOPSIS sys getuid / getuid = 24.(user ID in r0)

DESCRIPTION getuid returns `the real user ID of the current process.The real user ID identifies the person who is logged in,

in contradistinction to the effective user ID, whichdetermines his access permission at each moment. It is thus useful to programs which operate using the "set userID" mode, to find out who invoked them.

FILES /etc/uids can be used to map the user ID number into aname.
SEE_ALSO setuid
OWNER ken, dmr