getresuid(2) — Linux manual page

getresuid(2)               System Calls Manual               getresuid(2)

NAME         top

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

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #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         top

       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         top

       On success, zero is returned.  On error, -1 is returned, and errno
       is set to indicate the error.

ERRORS         top

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

STANDARDS         top

       None.  These calls also appear on HP-UX and some of the BSDs.

HISTORY         top

       Linux 2.1.44, glibc 2.3.2.

       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         top

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

COLOPHON         top

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Linux man-pages 6.15            2025-05-17                   getresuid(2)

Pages that refer to this page: getgid(2),  getuid(2),  setresuid(2),  syscalls(2),  id_t(3type),  credentials(7)

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