NAME
getuid,
geteuid —
get
user identification
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
uid_t
getuid(
void);
uid_t
geteuid(
void);
DESCRIPTION
The
getuid() function returns the real user ID of the calling
process. The
geteuid() function 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,
getuid() is used to determine the real-user-id of the
calling process.
ERRORS
The
getuid() and
geteuid() functions are
always successful, and no return value is reserved to indicate an error.
SEE ALSO
getgid(2),
setreuid(2)
STANDARDS
The
geteuid() and
getuid() functions conform
to
IEEE Std 1003.1-1990 (“POSIX.1”).
HISTORY
The
getuid() function appeared in
Version 4 AT&T UNIX.