NAME

       getresgid, getresuid, setresgid, setresuid — get or set real, effective and saved user or group ID

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <sys/types.h>
       #include <unistd.h>

       int
       getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);

       int
       getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);

       int
       setresgid(gid_t rgid, gid_t egid, gid_t sgid);

       int
       setresuid(uid_t ruid, uid_t euid, uid_t suid);

DESCRIPTION

       The  setresuid()  system  call  sets  the real, effective and saved user IDs of the current process.  The
       analogous setresgid() sets the real, effective and saved group IDs.

       Privileged processes may set these IDs to arbitrary values.  Unprivileged  processes  are  restricted  in
       that each of the new IDs must match one of the current IDs.

       Passing -1 as an argument causes the corresponding value to remain unchanged.

       The  getresgid()  and getresuid() calls retrieve the real, effective, and saved group and user IDs of the
       current process, respectively.

RETURN VALUES

       Upon successful completion, the value 0 is returned; otherwise the value -1 is returned  and  the  global
       variable errno is set to indicate the error.

ERRORS

       [EPERM]            The  calling process was not privileged and tried to change one or more IDs to a value
                          which was not the current real ID, the current effective ID nor the current saved ID.

       [EFAULT]           An address passed to getresgid() or getresuid() was invalid.

SEE ALSO

       getegid(2),  geteuid(2),  getgid(2),  getuid(2),  issetugid(2),  setgid(2),   setregid(2),   setreuid(2),
       setuid(2)

HISTORY

       These functions first appeared in HP-UX.

Debian                                          February 7, 2015                                    SETRESUID(2)