php man page for getresgid

GETRESUID(2)						     Linux Programmer's Manual						      GETRESUID(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 getre-
       suid32()  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 4.15 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)