Provided by: login_4.1.4.2+svn3283-3ubuntu5_amd64 bug

NOME

       login - begin session on the system

SINOSSI

       login [-p] [-h host] [username] [ENV=VAR...]

       login [-p] [-h host] -f username

       login [-p] -r host

DESCRIZIONE

       The login program is used to establish a new session with the system. It is normally
       invoked automatically by responding to the login: prompt on the user's terminal.  login
       may be special to the shell and may not be invoked as a sub-process. When called from a
       shell, login should be executed as exec login which will cause the user to exit from the
       current shell (and thus will prevent the new logged in user to return to the session of
       the caller). Attempting to execute login from any shell but the login shell will produce
       an error message.

       All'utente viene quindi chiesta la password, se necessario. Durante questa operazione
       l'eco sul terminale è disabilitato per non rivelare la password. Solo un basso numero di
       tentativi falliti è permesso prima che login termini e che la connessione sia rallentata.

       Se la scadenza delle password è abilitata per il proprio account, prima di proseguire ci
       può essere la richiesta di una nuova password. Il programma chiederà prima la vecchia
       password e poi la nuova per poter continuare. Per maggiori informazioni si faccia
       riferimento a passwd(1).

       Your user and group ID will be set according to their values in the /etc/passwd file. The
       value for $HOME, $SHELL, $PATH, $LOGNAME, and $MAIL are set according to the appropriate
       fields in the password entry. Ulimit, umask and nice values may also be set according to
       entries in the GECOS field.

       In alcune installazioni la variabile d'ambiente $TERM può essere impostata in base al tipo
       di terminale della propria connessione, come specificato in /etc/ttytype.

       An initialization script for your command interpreter may also be executed. Please see the
       appropriate manual section for more information on this function.

       A subsystem login is indicated by the presence of a "*" as the first character of the
       login shell. The given home directory will be used as the root of a new file system which
       the user is actually logged into.

       The login program is NOT responsible for removing users from the utmp file. It is the
       responsibility of getty(8) and init(8) to clean up apparent ownership of a terminal
       session. If you use login from the shell prompt without exec, the user you use will
       continue to appear to be logged in even after you log out of the "subsession".

OPZIONI

       -f
           Non effettua l'autenticazione, l'utente è già autenticato

           Note: In that case, username is mandatory.

       -h
           Nome dell'host remoto per questo login.

       -p
           Non modifica l'ambiente.

       -r
           Perform autologin protocol for rlogin.

       Le opzioni -r, -h e -f possono essere utilizzate solo quando login viene invocato da root.

AVVISI/CAVEAT

       This version of login has many compilation options, only some of which may be in use at
       any particular site.

       The location of files is subject to differences in system configuration.

       The login program is NOT responsible for removing users from the utmp file. It is the
       responsibility of getty(8) and init(8) to clean up apparent ownership of a terminal
       session. If you use login from the shell prompt without exec, the user you use will
       continue to appear to be logged in even after you log out of the "subsession".

       As with any program, login's appearance can be faked. If non-trusted users have physical
       access to a machine, an attacker could use this to obtain the password of the next person
       coming to sit in front of the machine. Under Linux, the SAK mechanism can be used by users
       to initiate a trusted path and prevent this kind of attack.

CONFIGURATION

       The following configuration variables in /etc/login.defs change the behavior of this tool:

       CONSOLE_GROUPS (string)
           List of groups to add to the user's supplementary groups set when logging in on the
           console (as determined by the CONSOLE setting). Default is none.

           Use with caution - it is possible for users to gain permanent access to these groups,
           even when not logged in on the console.

       DEFAULT_HOME (boolean)
           Indicate if login is allowed if we can't cd to the home directory. Default in no.

           If set to yes, the user will login in the root (/) directory if it is not possible to
           cd to her home directory.

       ENV_PATH (string)
           If set, it will be used to define the PATH environment variable when a regular user
           login. The value can be preceded by PATH=, or a colon separated list of paths (for
           example /bin:/usr/bin). The default value is PATH=/bin:/usr/bin.

       ENV_SUPATH (string)
           If set, it will be used to define the PATH environment variable when the superuser
           login. The value can be preceded by PATH=, or a colon separated list of paths (for
           example /sbin:/bin:/usr/sbin:/usr/bin). The default value is
           PATH=/sbin:/bin:/usr/sbin:/usr/bin.

       ERASECHAR (number)
           Terminal ERASE character (010 = backspace, 0177 = DEL).

           The value can be prefixed "0" for an octal value, or "0x" for an hexadecimal value.

       FAIL_DELAY (number)
           Delay in seconds before being allowed another attempt after a login failure.

       FAKE_SHELL (string)
           If set, login will execute this shell instead of the users' shell specified in
           /etc/passwd.

       HUSHLOGIN_FILE (string)
           If defined, this file can inhibit all the usual chatter during the login sequence. If
           a full pathname is specified, then hushed mode will be enabled if the user's name or
           shell are found in the file. If not a full pathname, then hushed mode will be enabled
           if the file exists in the user's home directory.

       KILLCHAR (number)
           Terminal KILL character (025 = CTRL/U).

           The value can be prefixed "0" for an octal value, or "0x" for an hexadecimal value.

       LOGIN_RETRIES (number)
           Maximum number of login retries in case of bad password.

           This will most likely be overridden by PAM, since the default pam_unix module has it's
           own built in of 3 retries. However, this is a safe fallback in case you are using an
           authentication module that does not enforce PAM_MAXTRIES.

       LOGIN_TIMEOUT (number)
           Max time in seconds for login.

       LOG_OK_LOGINS (boolean)
           Enable logging of successful logins.

       LOG_UNKFAIL_ENAB (boolean)
           Enable display of unknown usernames when login failures are recorded.

           Note: logging unknown usernames may be a security issue if an user enter her password
           instead of her login name.

       TTYGROUP (string), TTYPERM (string)
           The terminal permissions: the login tty will be owned by the TTYGROUP group, and the
           permissions will be set to TTYPERM.

           By default, the ownership of the terminal is set to the user's primary group and the
           permissions are set to 0600.

           TTYGROUP can be either the name of a group or a numeric group identifier.

           If you have a write program which is "setgid" to a special group which owns the
           terminals, define TTYGROUP to the group number and TTYPERM to 0620. Otherwise leave
           TTYGROUP commented out and assign TTYPERM to either 622 or 600.

       TTYTYPE_FILE (string)
           If defined, file which maps tty line to TERM environment parameter. Each line of the
           file is in a format something like "vt100 tty01".

       USERGROUPS_ENAB (boolean)
           If set to yes, userdel will remove the user's group if it contains no more members,
           and useradd will create by default a group with the name of the user.

FILE

       /var/run/utmp
           Elenco delle sessioni attive

       /var/log/wtmp
           Elenco delle precedenti sessioni.

       /etc/passwd
           informazioni sugli account utente.

       /etc/shadow
           Informazioni sicure sugli account di utenti.

       /etc/motd
           System message of the day file.

       /etc/nologin
           Inibisce l\'accesso al sistema per utenti diversi da root.

       /etc/ttytype
           Elenco di tipi di terminale.

       $HOME/.hushlogin
           #-#-#-#-# #-#-#-#-# Non fa mostrare i messaggi di sistema. #-#-#-#-# #-#-#-#-#
           Impedisce che vengano mostrati i messaggi di sistema.

       /etc/login.defs
           Shadow password suite configuration.

VEDERE ANCHE

       mail(1), passwd(1), sh(1), su(1), login.defs(5), nologin(5), passwd(5), securetty(5),
       getty(8).