SETREGID(2) System Calls Manual SETREGID(2)
setregid -- set real and effective group ID's
Standard C Library (libc, -lc)
setregid(gid_t rgid, gid_t egid);
This interface is made obsolete by the saved ID functionality in
setgid(2) and setegid(2).
The real and effective group ID's of the current process are set
according to the arguments. If the real group ID is changed, the saved
group ID is changed to the new value of the effective group ID.
If rgid or egid is -1, the current gid is filled in by the system.
Unprivileged users may change the real group ID to the effective group
ID, and may change the effective group ID to the real group ID or the
saved group ID; only the super-user may make other changes.
The setregid() function has been used to swap 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() function (see setgid(2)).
When setting the real and effective group IDs to the same value, this
function is equivalent to the setgid() function. When setting only the
effective group ID, this function is equivalent to the setegid()
Upon successful completion, a value of 0 is returned. Otherwise, a value
of -1 is returned and errno is set to indicate the error.
[EPERM] The current process is not the super-user and a change
other than changing the effective group-id to the real
group-id was specified.
getgid(2), setegid(2), setgid(2), setuid(2)
The setregid() function call appeared in 4.2BSD. An incompatible version
was implemented in 4.4BSD. It was reimplemented in NetBSD 1.2 in a way
compatible with 4.3BSD, SunOS and Linux, but should not be used in new
NetBSD 6.1.5 January 5, 2001 NetBSD 6.1.5