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  5.10  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)