To find out what groups you belong to, "for" your entry in /etc/passwd :
[If that didn't work, try a command like
With BSD UNIX, you're always a member of all your groups. This means that I can access files that are owned by the staff , power , and weakness groups, without doing anything in particular. Under System V UNIX, you can only be "in" one group at a time, even though you can be a member of several. (I suppose this is like social clubs; you can belong to the Elks and the Odd Fellows, but you can only wear one silly hat at a time.) If you need to access files that are owned by another group, use the newgrp command:
(System V even lets you change to groups that you don't belong to. In
this case, you have to give a
. Group passwords are
rarely used - usually, the password field is filled with a
On most systems, there are groups for major projects or departments, groups for system administration, and maybe one or two groups for visitors. Some BSD-based systems have a wheel group; to become, you must belong to wheel . Many systems make terminals writable only by the owner and a special group named tty ; this prevents other users from sending characters to your terminal without using an approved program like .