Name

getuid, geteuid — get user identity

Synopsis

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

DESCRIPTION

getuid() returns the real user ID of the calling process.

geteuid() returns the effective user ID of the calling process.

ERRORS

These functions are always successful.

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, 4.3BSD.

NOTES

History

In UNIX V6 the getuid() call returned (euid << 8) + uid. UNIX V7 introduced separate calls getuid() and geteuid().

The original Linux getuid() and geteuid() system calls supported only 16-bit user IDs. Subsequently, Linux 2.4 added getuid32() and geteuid32(), supporting 32-bit IDs. The glibc getuid() and geteuid() wrapper functions transparently deal with the variations across kernel versions.

SEE ALSO

getresuid(2), setreuid(2), setuid(2), credentials(7)

COLOPHON

This page is part of release 4.07 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man−pages/.


  Copyright 1993 Rickard E. Faith (faithcs.unc.edu)

%%%LICENSE_START(VERBATIM)
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Since the Linux kernel and libraries are constantly changing, this
manual page may be incorrect or out-of-date.  The author(s) assume no
responsibility for errors or omissions, or for damages resulting from
the use of the information contained herein.  The author(s) may not
have taken the same level of care in the production of this manual,
which is licensed free of charge, as they might when working
professionally.

Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
%%%LICENSE_END

Historical remark, aeb, 2004-06-05