[OpenBSD]

Manual Page Search Parameters

GETUID(2) System Calls Manual GETUID(2)

getuid, geteuid
get user identification

#include <unistd.h>
uid_t
getuid(void);
uid_t
geteuid(void);

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.

The getuid() and geteuid() functions are always successful, and no return value is reserved to indicate an error.

getgid(2), getresuid(2), setreuid(2), setuid(2)

The getuid() and geteuid() functions conform to IEEE Std 1003.1-2008 (“POSIX.1”).

The getuid() system call first appeared in Version 1 AT&T UNIX, and geteuid() in Version 7 AT&T UNIX.
September 10, 2015 OpenBSD-current