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

NAME         top

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

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 appropriately.

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 4.15 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                            2017-09-15                     GETRESUID(2)

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

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