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

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