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NAME | SYNOPSIS | DESCRIPTION | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
GETUID(2) Linux Programmer's Manual GETUID(2)
getuid, geteuid - get user identity
#include <unistd.h>
#include <sys/types.h>
uid_t getuid(void);
uid_t geteuid(void);
getuid() returns the real user ID of the calling process.
geteuid() returns the effective user ID of the calling process.
These functions are always successful.
POSIX.1-2001, POSIX.1-2008, 4.3BSD.
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.
On Alpha, instead of a pair of getuid() and geteuid() system calls, a
single getxuid() system call is provided, which returns a pair of
real and effective UIDs. The glibc getuid() and geteuid() wrapper
functions transparently deal with this. See syscall(2) for details
regarding register mapping.
getresuid(2), setreuid(2), setuid(2), credentials(7)
This page is part of release 5.08 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/.
Linux 2019-03-06 GETUID(2)
Pages that refer to this page: gawk(1) , procps(1) , ps(1) , strace(1) , setegid(2) , seteuid(2) , syscalls(2) , cuserid(3) , getlogin(3) , getlogin_r(3) , pam_close_session(3) , pam_open_session(3) , credentials(7) , signal-safety(7)
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