Provided by: login_4.1.4.2-1ubuntu3_i386 bug

login -

login [  ]
       login -p
       login -h
       login -f

login

          (
           )

         root , /etc/nologin

       /etc/usertty
             ,

       , syslog

          " "

       /etc/securetty
        root

       syslog

        (   ) , 10   login
            ,
        (

       syslog

       .hushlogin $HOME  ,

       , /var/log/lastlog ,    , ,

       ,
         UID, GID
        TERM   , , ( -p

       HOME, PATH, SHELL, TERM, MAIL, LOGNAME
           ,
       /usr/local/bin:/bin:/usr/bin:.  root
       /sbin:/bin:/usr/sbin:/usr/bin
        "" ,  , /usr/spool/mail
             0 0

       /etc/passwd
          , /bin/sh

       , /etc/passwd
           , /
        ( .hushlogin
          )

       -p     login

              getty(8)

       -f      ( root   ,

       -h     ( telnetd(8)
               utmp, wtmp     root

       /etc/securetty
        root
         /dev/
        root

       /etc/usertty

       ,

       CLASSES, GROUPS, USERS  CLASSES
        ,  GROUPS
        , USERS

          255   , #

   CLASSES
       CLASSES   CLASSES

            ,

          GROUPS, USERS

       CLASSES  :

       CLASSES
       myclass1       tty1 tty2
       myclass2       tty3 @.foo.com

       myclass1 myclass2

   GROUPS
       GROUPS

       /etc/passwd

       /etc/group

       /etc/usertty
        GROUPS    ,

       GROUPS    GROUPS    ,

        CLASSES

       GROUPS  :

       GROUPS
       sys       tty1 @.bar.edu
       stud      myclass1 tty4

       sys
         bar.edu   , tty1

       stud
         myclass1  tty4

   USERS
       USERS   USERS

         ,

          CLASSES

       USERS  :

       USERS
       zacho          tty1 @130.225.16.0/255.255.255.0
       blue      tty3 myclass2

         zacho   IP  130.225.16.0 130.225.16.255
           tty1 blue   myclass2   tty3

       USERS     *
         ,

          USERS, GROUPS
           /

   Origins
          origin
         origin

       o        /dev/  , tty1, ttyS0

       o      @localhost   telnet/rlogin
                `xterm -e /bin/login'

       o      @.some.dom    rlogin/telnet

       o      IP   @x.x.x.x/y.y.y.y
               x.x.x.x  y.y.y.y  IP
                @130.225.16.0/255.255.254.0
                IP  130.225.16.0 - 130.225.17.255

        origin

       timespec    ::= '[' <day-or-hour> [':' <day-or-hour>]* ']'
       day         ::= 'mon' | 'tue' | 'wed' | 'thu' | 'fri' | 'sat' | 'sun'
       hour        ::= '0' | '1' | ... | '23'
       hourspec    ::= <hour> | <hour> '-' <hour>
       day-or-hour ::= <day> | <hourspec>

        [mon:tue:wed:thu:fri:8-17]tty3  ,   8 00 5 59 tty3       , a-b  a 00 b
       59
         (10) (10 0010 59)

       /etc/usertty
           ,

       /var/run/utmp
       /var/log/wtmp
       /var/log/lastlog
       /etc/motd
       /etc/passwd
       /etc/nologin
       /etc/usertty
       $HOME/.hushlogin

       init(8),   getty(8),   mail(1),   passwd(1),   passwd(5),   environ(7),
       shutdown(8)

  BSD
       -r

       rlogind(8)

Derived from BSD login 5.40 (5/9/89) by Michael Glad (glad@daimi.dk) for HP-UX

       Ported to Linux 0.12: Peter Orbaek (poe@daimi.aau.dk)