file specifies (user, host) combinations and/or (user, tty)
combinations for which a login will be either accepted or refused.
When someone logs in, the
is scanned for the first entry that
matches the (user, host) combination, or, in case of non-networked
logins, the first entry that matches the (user, tty) combination.
permissions field of that table entry determines whether the login will
be accepted or refused.
Each line of the login access control table has three fields separated by a
permission: users: origins
The first field should be a "+" (access granted) or "-" (access denied)
The second field should be a list of one or more login names,
group names, or ALL (always matches).
The third field should be a list
of one or more tty names (for non-networked logins), host names, domain
names (begin with "."), host addresses, internet network numbers (end
with "."), ALL (always matches) or LOCAL (matches any string that does
not contain a "." character).
If you run NIS you can use @netgroupname
in host or user patterns.
The EXCEPT operator makes it possible to write very compact rules.
The group file is searched only when a name does not match that of the
Only groups are matched in which users are explicitly
listed: the program does not look at a users primary group id value.