Similarly, a value assigned to ``$)'' must also be a space-separated list of numbers. The first number is used to set the effective gid, and the rest (if any) are passed to setgroups(). To get the effect of an empty list for setgroups(), just repeat the new effective gid; that is, to force an effective gid of 5 and an effectively empty setgroups() list, say

 $) = "5 5" 

(Mnemonic: parentheses are used to GROUP things. The effective gid is the group that's RIGHT for you, if you're running setgid.)

Note: ``$<'', ``$>'', ``$('' and ``$)'' can be set only on machines that support the corresponding set[re][ug]id() routine. ``$('' and ``$)'' can be swapped only on machines supporting setregid().