December 1, 2017
getuid, geteuid - get user identification
.In unistd.h uid_t
getuidsystem call returns the real user ID of the calling process. The
geteuidsystem call returns the effective user ID of the calling process.
The real user ID is that of the user who has invoked the program. As the effective user ID gives the process additional permissions during execution of "set-user-ID" mode processes,
getuidis used to determine the real-user-id of the calling process.
geteuidsystem calls are always successful, and no return value is reserved to indicate an error.
getuidsystem calls are expected to conform to -p1003.1-90.
getuidfunction appeared in AT&T v1 . The
geteuidfunction appeared in AT&T v4 .