NAME
getuid, geteuid
— get user
identification
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
STANDARDS
The getuid() and
geteuid() functions conform to IEEE
Std 1003.1-2008 (“POSIX.1”).
HISTORY
The getuid() system call first appeared in
Version 1 AT&T UNIX, and
geteuid() in Version 7
AT&T UNIX.