getresuid(2) — Linux manual page


GETRESUID(2)            Linux Programmer's Manual           GETRESUID(2)

NAME         top

       getresuid, getresgid - get real, effective, and saved user/group

SYNOPSIS         top

       #define _GNU_SOURCE         /* See feature_test_macros(7) */
       #include <unistd.h>

       int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);
       int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);

DESCRIPTION         top

       getresuid() returns the real UID, the effective UID, and the
       saved set-user-ID of the calling process, in the arguments ruid,
       euid, and suid, respectively.  getresgid() performs the analogous
       task for the process's group IDs.

RETURN VALUE         top

       On success, zero is returned.  On error, -1 is returned, and
       errno is set to indicate the error.

ERRORS         top

       EFAULT One of the arguments specified an address outside the
              calling program's address space.

VERSIONS         top

       These system calls appeared on Linux starting with kernel 2.1.44.

       The prototypes are given by glibc since version 2.3.2, provided
       _GNU_SOURCE is defined.

CONFORMING TO         top

       These calls are nonstandard; they also appear on HP-UX and some
       of the BSDs.

NOTES         top

       The original Linux getresuid() and getresgid() system calls
       supported only 16-bit user and group IDs.  Subsequently, Linux
       2.4 added getresuid32() and getresgid32(), supporting 32-bit IDs.
       The glibc getresuid() and getresgid() wrapper functions
       transparently deal with the variations across kernel versions.

SEE ALSO         top

       getuid(2), setresuid(2), setreuid(2), setuid(2), credentials(7)

COLOPHON         top

       This page is part of release 5.13 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

Linux                          2021-03-22                   GETRESUID(2)

Pages that refer to this page: getgid(2)getuid(2)setresuid(2)syscalls(2)credentials(7)system_data_types(7)