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 to indicate the
       error.

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 5.13 of the Linux man-pages project.  A  description  of  the
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       found at https://www.kernel.org/doc/man-pages/.