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getresgid(2)


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 4.09 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/.



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