SETREGID(2) OpenBSD Programmer's Manual SETREGID(2)NAMEsetregid - set real and effective group IDs
SYNOPSIS
#include <unistd.h>
int
setregid(gid_t rgid, gid_t egid);
DESCRIPTION
The real and effective group IDs of the current process are set according
to the arguments. The saved group ID will be set to the new value of the
real group ID if a real group ID is specified and either the new real
group ID value is different from the current value or the effective group
ID is changed to a value other than the current saved group ID.
Unprivileged users may change either group ID to the current value of the
real, effective, or saved group ID. Only the superuser may make other
changes.
Supplying a value of -1 for either the real or effective group ID forces
the system to substitute the current ID in place of the -1 parameter.
The setregid() function was intended to allow swapping the real and
effective group IDs in set-group-ID programs to temporarily relinquish
the set-group-ID value. This purpose is now better served by the use of
the setegid(2) function.
When setting the real and effective group IDs to the same value, the
setgid(2) function is preferred.
RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value
of -1 is returned and errno is set to indicate the error.
ERRORS
[EPERM] The current process is not the superuser and a change other
than changing the effective group ID to the real group ID
was specified.
SEE ALSOgetgid(2), setegid(2), setgid(2), setresgid(2), setreuid(2)STANDARDS
The setregid() function conforms to the IEEE Std 1003.1-2001 (``POSIX'')
and X/Open Portability Guide Issue 4.3 (``XPG4.3''). specifications.
Note, however, that prior to IEEE Std 1003.1-2001 (``POSIX''), the
setregid() function was not a part of the IEEE Std 1003.1 (``POSIX'')
specification. As a result, it may not be implemented on all systems.
HISTORY
The setregid() function call appeared in 4.2BSD. A semantically
different version appeared in 4.4BSD. The current version, with the
original semantics restored, appeared in OpenBSD 3.3.
CAVEATS
The setregid() function predates POSIX saved group IDs. This
implementation changes the saved group ID to the new value of the real
group ID only if the real group ID is specified and either changed or the
effective group ID is changed to a value other than the current saved
group ID. Other implementations may behave differently.
OpenBSD 4.9 August 4, 2008 OpenBSD 4.9