290 lines
6.7 KiB
Groff
290 lines
6.7 KiB
Groff
'\" t
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.\" Title: su
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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 "SU" "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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su \- cambia ID utente o diventa amministratore
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.SH "SINOSSI"
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.HP \w'\fBsu\fR\ 'u
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\fBsu\fR [\fIoptions\fR] [\fI\-\fR] [\fIusername\fR\ [\ \fIargs\fR\ ]]
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.SH "DESCRIZIONE"
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.PP
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The
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\fBsu\fR
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command is used to become another user during a login session\&. Invoked without a
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\fBusername\fR,
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\fBsu\fR
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defaults to becoming the superuser\&. The
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\fB\-\fR
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option may be used to provide an environment similar to what the user would expect had the user logged in directly\&. The
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\fB\-c\fR
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option may be used to treat the next argument as a command by most shells\&.
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.PP
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Options are recognized everywhere in the argument list\&. You can use the
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\fB\-\-\fR
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argument to stop option parsing\&. The
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\fB\-\fR
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option is special: it is also recognized after
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\fB\-\-\fR, but has to be placed before
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\fBusername\fR\&.
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.PP
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All\*(Aqutente viene quindi chiesta la password, se necessario\&. Una password errata viene segnalata da un messaggio d\*(Aqerrore\&. Viene effettuato il log di tutti i tentativi, siano essi riusciti o meno, al fine di rilevare ogni abuso del sistema\&.
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.PP
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The current environment is passed to the new shell\&. The value of
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\fB$PATH\fR
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is reset to
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/bin:/usr/bin
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for normal users, or
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/sbin:/bin:/usr/sbin:/usr/bin
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for the superuser\&. This may be changed with the
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\fBENV_PATH\fR
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and
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\fBENV_SUPATH\fR
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definitions in
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/etc/login\&.defs\&.
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.PP
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Un sottosistema di login \(`e indicato dalla presenza del carattere \(Fo*\(Fc all\*(Aqinizio della shell di login\&. La directory home impostata sar\(`a utilizzata come root di un nuovo file system al quale l\*(Aqutente accede\&.
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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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\fBsu\fR
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command are:
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.PP
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\fB\-c\fR, \fB\-\-command\fR\ \&\fICOMMAND\fR
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.RS 4
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Specify a command that will be invoked by the shell using its
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\fB\-c\fR\&.
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.sp
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The executed command will have no controlling terminal\&. This option cannot be used to execute interactive programs which need a controlling TTY\&.
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.RE
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.PP
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\fB\-\fR, \fB\-l\fR, \fB\-\-login\fR
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.RS 4
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Fornisce un ambiente simile a quello che un utente si attende quando effettua direttamente il login\&.
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.sp
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When
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\fB\-\fR
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is used, it must be specified before any
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\fBusername\fR\&. For portability it is recommended to use it as last option, before any
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\fBusername\fR\&. The other forms (\fB\-l\fR
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and
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\fB\-\-login\fR) do not have this restriction\&.
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.RE
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.PP
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\fB\-s\fR, \fB\-\-shell\fR\ \&\fISHELL\fR
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.RS 4
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La shell che verr\(`a invocata\&.
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.sp
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The invoked shell is chosen from (highest priority first):
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.PP
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.RS 4
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The shell specified with \-\-shell\&.
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.RE
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.PP
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.RS 4
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If
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\fB\-\-preserve\-environment\fR
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is used, the shell specified by the
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\fB$SHELL\fR
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environment variable\&.
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.RE
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.PP
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.RS 4
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The shell indicated in the
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/etc/passwd
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entry for the target user\&.
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.RE
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.PP
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.RS 4
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/bin/sh
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if a shell could not be found by any above method\&.
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.RE
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.sp
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If the target user has a restricted shell (i\&.e\&. the shell field of this user\*(Aqs entry in
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/etc/passwd
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is not listed in
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/etc/shells), then the
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\fB\-\-shell\fR
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option or the
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\fB$SHELL\fR
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environment variable won\*(Aqt be taken into account, unless
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\fBsu\fR
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is called by root\&.
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.RE
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.PP
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\fB\-m\fR, \fB\-p\fR, \fB\-\-preserve\-environment\fR
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.RS 4
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Preserve the current environment, except for:
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.PP
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\fB$PATH\fR
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.RS 4
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reset according to the
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/etc/login\&.defs
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options
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\fBENV_PATH\fR
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or
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\fBENV_SUPATH\fR
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(see below);
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.RE
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.PP
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\fB$IFS\fR
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.RS 4
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reset to
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\(Fo<space><tab><newline>\(Fc, if it was set\&.
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.RE
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.sp
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If the target user has a restricted shell, this option has no effect (unless
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\fBsu\fR
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is called by root)\&.
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.sp
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Note that the default behavior for the environment is the following:
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.PP
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.RS 4
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The
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\fB$HOME\fR,
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\fB$SHELL\fR,
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\fB$USER\fR,
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\fB$LOGNAME\fR,
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\fB$PATH\fR, and
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\fB$IFS\fR
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environment variables are reset\&.
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.RE
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.PP
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.RS 4
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If
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\fB\-\-login\fR
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is not used, the environment is copied, except for the variables above\&.
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.RE
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.PP
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.RS 4
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If
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\fB\-\-login\fR
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is used, the
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\fB$TERM\fR,
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\fB$COLORTERM\fR,
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\fB$DISPLAY\fR, and
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\fB$XAUTHORITY\fR
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environment variables are copied if they were set\&.
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.RE
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.PP
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.RS 4
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If
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\fB\-\-login\fR
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is used, the
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\fB$TZ\fR,
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\fB$HZ\fR, and
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\fB$MAIL\fR
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environment variables are set according to the
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/etc/login\&.defs
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options
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\fBENV_TZ\fR,
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\fBENV_HZ\fR,
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\fBMAIL_DIR\fR, and
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\fBMAIL_FILE\fR
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(see below)\&.
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.RE
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.PP
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.RS 4
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If
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\fB\-\-login\fR
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is used, other environment variables might be set by the
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\fBENVIRON_FILE\fR
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file (see below)\&.
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.RE
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.sp
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.RE
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.SH "AVVISI/CAVEAT"
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.PP
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This version of
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\fBsu\fR
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has many compilation options, only some of which may be in use at any particular site\&.
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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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On success,
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\fBsu\fR
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returns the exit value of the command it executed\&.
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.PP
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If this command was terminated by a signal,
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\fBsu\fR
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returns the number of this signal plus 128\&.
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.PP
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If su has to kill the command (because it was asked to terminate, and the command did not terminate in time),
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\fBsu\fR
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returns 255\&.
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.PP
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Some exit values from
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\fBsu\fR
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are independent from the executed command:
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.PP
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\fI0\fR
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.RS 4
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success (\fB\-\-help\fR
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only)
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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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System or authentication failure
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.RE
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.PP
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\fI126\fR
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.RS 4
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The requested command was not found
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.RE
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.PP
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\fI127\fR
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.RS 4
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The requested command could not be executed
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.RE
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.SH "VEDERE ANCHE"
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.PP
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\fBlogin\fR(1),
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\fBlogin.defs\fR(5),
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\fBsg\fR(1),
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\fBsh\fR(1)\&.
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