The real gid of this process. If you are on a machine that supports membership in multiple groups simultaneously, gives a space separated list of groups you are in. The first number is the one returned by getgid()
, and the subsequent ones by getgroups()
, one of which may be the same as the first number.
However, a value assigned to $(
must be a single number used to set the real gid. So the value given by $(
should not be assigned back to $(
without being forced numeric, such as by adding zero. Note that this is different to the effective gid ($)
) which does take a list.
You can change both the real gid and the effective gid at the same time by using POSIX::setgid()
. Changes to $(
require a check to $!
to detect any possible errors after an attempted change.
Mnemonic: parentheses are used to group things. The real gid is the group you left, if you're running setgid.