NAME

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

SYNOPSIS

       #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

       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

       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

ERRORS

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

VERSIONS

       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

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

NOTES

       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

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

COLOPHON

       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/.