SETREGID(2) System Calls SETREGID(2)

NAME

setregid - set real and effective group IDs

SYNOPSIS

#include <unistd.h>

int setregid(gid_t rgid, gid_t egid);

DESCRIPTION

The setregid() function is used to set the real and effective group IDs
of the calling process. If rgid is -1, the real group ID is not changed;
if egid is -1, the effective group ID is not changed. The real and
effective group IDs may be set to different values in the same call.


If the {PRIV_PROC_SETID} privilege is asserted in the effective set of
the calling process, the real group ID and the effective group ID can be
set to any legal value.


If the {PRIV_PROC_SETID} privilege is not asserted in the effective set
of the calling process, either the real group ID can be set to the saved
set-group-ID from execve(2), or the effective group ID can either be set
to the saved set-group-ID or the real group ID.


In either case, if the real group ID is being changed (that is, if rgid
is not -1), or the effective group ID is being changed to a value not
equal to the real group ID, the saved set-group-ID is set equal to the
new effective group ID.

RETURN VALUES

Upon successful completion, 0 is returned. Otherwise, -1 is returned,
errno is set to indicate the error, and neither of the group IDs will be
changed.

ERRORS

The setregid() function will fail if:

EINVAL
The value of rgid or egid is less than 0 or greater than
UID_MAX (defined in <limits.h>).


EPERM
The {PRIV_PROC_SETID} privilege is not asserted in the
effective set of the calling processes and a change was
specified other than changing the real group ID to the saved
set-group-ID or changing the effective group ID to the real
group ID or the saved group ID.

USAGE

If a set-group-ID process sets its effective group ID to its real group
ID, it can still set its effective group ID back to the saved set-
group-ID.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+

SEE ALSO

execve(2), getgid(2), setreuid(2), setuid(2), attributes(7),
privileges(7), standards(7)

March 22, 2004 SETREGID(2)