Linux
2017-09-15
Aliases: getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid(2), getresgid32(2), getresgid32(2), getresgid32(2), getresuid32(2), getresuid32(2), getresuid32(2), getresuid32(2), getresuid32(2), getresuid32(2), getresuid32(2), getresuid32(2), getresuid32(2), getresuid32(2)
manpages-dev
Manual pages about using GNU/Linux for development
man-pages
Linux kernel and C library user-space interface documentation
NAME
getresuid, getresgid - get real, effective and saved user/group IDs
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <unistd.h>
#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);
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.
