264 lines
9.5 KiB
Groff
264 lines
9.5 KiB
Groff
'\" t
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.\" Title: passwd
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.\" Author: Julianne Frances Haugh
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.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
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.\" Date: 19/03/2025
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.\" Manual: User Commands
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.\" Source: shadow-utils 4.17.4
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.\" Language: Italian
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.\"
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.TH "PASSWD" "1" "19/03/2025" "shadow\-utils 4\&.17\&.4" "User Commands"
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.\" -----------------------------------------------------------------
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.\" * Define some portability stuff
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.\" -----------------------------------------------------------------
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.\" http://bugs.debian.org/507673
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.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.ie \n(.g .ds Aq \(aq
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.el .ds Aq '
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.\" -----------------------------------------------------------------
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.\" * set default formatting
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.\" -----------------------------------------------------------------
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.\" disable hyphenation
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.nh
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.\" disable justification (adjust text to left margin only)
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.ad l
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.\" -----------------------------------------------------------------
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.\" * MAIN CONTENT STARTS HERE *
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.\" -----------------------------------------------------------------
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.SH "NOME"
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passwd \- cambia la password utente
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.SH "SINOSSI"
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.HP \w'\fBpasswd\fR\ 'u
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\fBpasswd\fR [\fIoptions\fR] [\fILOGIN\fR]
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.SH "DESCRIZIONE"
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.PP
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The
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\fBpasswd\fR
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command changes passwords for user accounts\&. A normal user may only change the password for their own account, while the superuser may change the password for any account\&.
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\fBpasswd\fR
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also changes the account or associated password validity period\&.
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.SS "Modifiche delle password"
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.PP
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All\*(Aqutente viene prima chiesta la propria password attuale, se presente\&. Questa password viene cifrata e confrontata con quella memorizzata\&. All\*(Aqutente viene data solo una possibilit\(`a di inserire la password corretta\&. Il super utente salta questo passo in modo da poter modificare password dimenticate\&.
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.PP
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After the password has been entered, password aging information is checked to see if the user is permitted to change the password at this time\&. If not,
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\fBpasswd\fR
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refuses to change the password and exits\&.
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.PP
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All\*(Aqutente viene quindi chiesto di inserire la nuova password due volte\&. Le due password sono confrontate e devono essere uguali affinch\('e la password venga accettata\&.
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.PP
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Then, the password is tested for complexity\&.
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\fBpasswd\fR
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will reject any password which is not suitably complex\&. Care must be taken not to include the system default erase or kill characters\&.
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.SS "Suggerimenti per password utente"
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.PP
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The security of a password depends upon the strength of the encryption algorithm and the size of the key space\&. The legacy
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\fIUNIX\fR
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System encryption method is based on the NBS DES algorithm\&. More recent methods are now recommended (see
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\fBENCRYPT_METHOD\fR)\&. The size of the key space depends upon the randomness of the password which is selected\&.
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.PP
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La compromissione di una password avviene normalmente a seguito di incuria nella scelta o nella gestione della password\&. Per questo motivo non si devono utilizzare password che appaiono nei dizionari o che devono essere scritte\&. La password non deve essere uno nome proprio, il numero della patente, la data di nascita o l\*(Aqindirizzo\&. Uno qualunque di questi potrebbe essere indovinato per violare la sicurezza del sistema\&.
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.PP
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As a general guideline, passwords should be long and random\&. It\*(Aqs fine to use simple character sets, such as passwords consisting only of lowercase letters, if that helps memorizing longer passwords\&. For a password consisting only of lowercase English letters randomly chosen, and a length of 32, there are 26^32 (approximately 2^150) different possible combinations\&. Being an exponential equation, it\*(Aqs apparent that the exponent (the length) is more important than the base (the size of the character set)\&.
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.PP
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You can find advice on how to choose a strong password on https://en\&.wikipedia\&.org/wiki/Password_strength
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.SH "OPZIONI"
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.PP
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The options which apply to the
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\fBpasswd\fR
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command are:
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.PP
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\fB\-a\fR, \fB\-\-all\fR
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.RS 4
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This option can be used only with
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\fB\-S\fR
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and causes show status for all users\&.
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.RE
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.PP
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\fB\-d\fR, \fB\-\-delete\fR
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.RS 4
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Cancella la password utente (la rende vuota)\&. Questo \(`e un metodo veloce per disabilitare la password per l\*(Aqaccount\&. Imposta l\*(Aqaccount indicato come senza password\&.
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.RE
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.PP
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\fB\-e\fR, \fB\-\-expire\fR
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.RS 4
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Fa scadere subito la password dell\*(Aqutente\&. Il che ha l\*(Aqeffetto di forzare un cambio password al successivo accesso da parte dell\*(Aqutente\&.
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.RE
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.PP
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\fB\-h\fR, \fB\-\-help\fR
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.RS 4
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Mostra un messaggio di aiuto ed esce\&.
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.RE
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.PP
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\fB\-i\fR, \fB\-\-inactive\fR\ \&\fIINACTIVE\fR
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.RS 4
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This option is used to disable an account after the password has been expired for a number of days\&. After a user account has had an expired password for
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\fIINACTIVE\fR
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days, the user may no longer sign on to the account\&.
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.RE
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.PP
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\fB\-k\fR, \fB\-\-keep\-tokens\fR
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.RS 4
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Indica che il cambio password va effettuato solo per i token (password) di autenticazione scaduti\&. L\*(Aqutente vuole mantenere inalterati i token non scaduti\&.
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.RE
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.PP
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\fB\-l\fR, \fB\-\-lock\fR
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.RS 4
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Blocca la password dell\*(Aqaccount indicato\&. Questa opzione disabilita una password modificandola in modo che non corrisponda a nessun valore cifrato (aggiunge un \(Fo!\(Fc all\*(Aqinizio della password)\&.
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.sp
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Note that this does not disable the account\&. The user may still be able to login using another authentication token (e\&.g\&. an SSH key)\&. To disable the account, administrators should use
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\fBusermod \-\-expiredate 1\fR
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(this sets the account\*(Aqs expire date to Jan 2, 1970)\&.
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.sp
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Gli utenti con password bloccata non la possono cambiare\&.
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.RE
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.PP
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\fB\-n\fR, \fB\-\-mindays\fR\ \&\fIMIN_DAYS\fR
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.RS 4
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Set the minimum number of days between password changes to
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\fIMIN_DAYS\fR\&. A value of zero for this field indicates that the user may change their password at any time\&.
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.RE
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.PP
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\fB\-q\fR, \fB\-\-quiet\fR
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.RS 4
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Modalit\(`a silenziosa\&.
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.RE
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.PP
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\fB\-r\fR, \fB\-\-repository\fR\ \&\fIREPOSITORY\fR
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.RS 4
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change password in
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\fIREPOSITORY\fR
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repository
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.RE
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.PP
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\fB\-R\fR, \fB\-\-root\fR\ \&\fICHROOT_DIR\fR
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.RS 4
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Apply changes in the
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\fICHROOT_DIR\fR
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directory and use the configuration files from the
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\fICHROOT_DIR\fR
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directory\&. Only absolute paths are supported\&.
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.RE
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.PP
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\fB\-P\fR, \fB\-\-prefix\fR\ \&\fIPREFIX_DIR\fR
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.RS 4
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Apply changes to configuration files under the root filesystem found under the directory
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\fIPREFIX_DIR\fR\&. This option does not chroot and is intended for preparing a cross\-compilation target\&. Some limitations: NIS and LDAP users/groups are not verified\&. No PAM support\&. No SELINUX support\&.
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.RE
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.PP
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\fB\-S\fR, \fB\-\-status\fR
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.RS 4
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Visualizza le informazioni sullo stato di un account\&. Lo stato consiste di 7 campi\&. Il primo campo \(`e il nome dell\*(Aqutente\&. Il secondo campo indica se l\*(Aqaccount ha una password bloccata (L), non ha password (NP) o ha una password valida (P)\&. Il terzo campo contiene la data di ultima modifica della password\&. I successivi quattro campi sono l\*(Aqet\(`a minima, la massima, il periodo di avviso e quello di inattivit\(`a\&. Queste et\(`a sono espresse in giorni\&.
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.RE
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.PP
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\fB\-u\fR, \fB\-\-unlock\fR
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.RS 4
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Unlock the password of the named account\&. This option re\-enables a password by changing the password back to its previous value (to the value before using the
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\fB\-l\fR
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option)\&.
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.RE
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.PP
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\fB\-w\fR, \fB\-\-warndays\fR\ \&\fIWARN_DAYS\fR
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.RS 4
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Set the number of days of warning before a password change is required\&. The
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\fIWARN_DAYS\fR
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option is the number of days prior to the password expiring that a user will be warned that their password is about to expire\&.
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.RE
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.PP
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\fB\-x\fR, \fB\-\-maxdays\fR\ \&\fIMAX_DAYS\fR
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.RS 4
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Set the maximum number of days a password remains valid\&. After
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\fIMAX_DAYS\fR, the password is required to be changed\&.
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.sp
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Passing the number
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\fI\-1\fR
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as
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\fIMAX_DAYS\fR
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will remove checking a password\*(Aqs validity\&.
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.RE
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.PP
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\fB\-s\fR, \fB\-\-stdin\fR
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.RS 4
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This option is used to indicate that passwd should read the new password from standard input, which can be a pipe\&.
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.RE
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.SH "AVVISI/CAVEAT"
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.PP
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Il controllo della complessit\(`a delle password varia da sistema a sistema\&. All\*(Aqutente \(`e caldamente consigliato si utilizzare una password che ritenga sufficientemente complessa\&.
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.PP
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Gli utenti possono non essere in grado di cambiare la propria password se NIS \(`e abilitato ed essi non sono collegati al server NIS\&.
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.SH "CONFIGURAZIONE"
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.PP
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The following configuration variables in
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/etc/login\&.defs
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change the behavior of this tool:
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.SH "FILE"
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.PP
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/etc/passwd
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.RS 4
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Informazioni sugli account utente\&.
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.RE
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.PP
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/etc/shadow
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.RS 4
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Informazioni sicure sugli account utente\&.
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.RE
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.PP
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/etc/login\&.defs
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.RS 4
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Configurazione del pacchetto password shadow
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.RE
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.SH "VALORI RESTITUITI"
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.PP
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The
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\fBpasswd\fR
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command exits with the following values:
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.PP
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\fI0\fR
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.RS 4
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success
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.RE
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.PP
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\fI1\fR
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.RS 4
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permission denied
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.RE
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.PP
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\fI2\fR
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.RS 4
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invalid combination of options
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.RE
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.PP
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\fI3\fR
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.RS 4
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unexpected failure, nothing done
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.RE
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.PP
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\fI4\fR
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.RS 4
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unexpected failure,
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passwd
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file missing
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.RE
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.PP
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\fI5\fR
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.RS 4
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passwd
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file busy, try again
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.RE
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.PP
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\fI6\fR
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.RS 4
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invalid argument to option
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.RE
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.SH "VEDERE ANCHE"
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.PP
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\fBchpasswd\fR(8),
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\fBmakepasswd\fR(1),
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\fBpasswd\fR(5),
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\fBshadow\fR(5),
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\fBlogin.defs\fR(5),
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\fBusermod\fR(8)\&.
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.PP
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The following web page comically (yet correctly) compares the strength of two different methods for choosing a password: "https://xkcd\&.com/936/"
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