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'\" t
.\" Title: login
.\" Author: Julianne Frances Haugh
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\" Date: 21.06.2024
.\" Manual: User Commands
.\" Source: shadow-utils 4.15.2
.\" Language: German
.\"
.TH "LOGIN" "1" "21.06.2024" "shadow\-utils 4\&.15\&.2" "User Commands"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
login \- startet eine Sitzung auf dem System
.SH "\(:UBERSICHT"
.HP \w'\fBlogin\fR\ 'u
\fBlogin\fR [\-p] [\-h\ \fIhost\fR] [\fIusername\fR] [\fIENV=VAR\fR...]
.HP \w'\fBlogin\fR\ 'u
\fBlogin\fR [\-p] [\-h\ \fIhost\fR] \-f \fIusername\fR
.HP \w'\fBlogin\fR\ 'u
\fBlogin\fR [\-p] \-r\ \fIhost\fR
.SH "BESCHREIBUNG"
.PP
The
\fBlogin\fR
program is used to establish a new session with the system\&. It is normally invoked automatically by responding to the
\fIlogin:\fR
prompt on the user\*(Aqs terminal\&.
\fBlogin\fR
may be special to the shell and may not be invoked as a sub\-process\&. When called from a shell,
\fBlogin\fR
should be executed as
\fBexec login\fR
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
\fBlogin\fR
from any shell but the login shell will produce an error message\&.
.PP
The user is then prompted for a password, where appropriate\&. Echoing is disabled to prevent revealing the password\&. Only a small number of password failures are permitted before
\fBlogin\fR
exits and the communications link is severed\&.
.PP
If password aging has been enabled for your account, you may be prompted for a new password before proceeding\&. You will be forced to provide your old password and the new password before continuing\&. Please refer to
\fBpasswd\fR(1)
for more information\&.
.PP
After a successful login, you will be informed of any system messages and the presence of mail\&. You may turn off the printing of the system message file,
/etc/motd, by creating a zero\-length file
\&.hushlogin
in your login directory\&. The mail message will be one of "\fIYou have new mail\&.\fR", "\fIYou have mail\&.\fR", or "\fINo Mail\&.\fR" according to the condition of your mailbox\&.
.PP
Your user and group ID will be set according to their values in the
/etc/passwd
file\&. The value for
\fB$HOME\fR,
\fB$SHELL\fR,
\fB$PATH\fR,
\fB$LOGNAME\fR, and
\fB$MAIL\fR
are set according to the appropriate fields in the password entry\&. Ulimit, umask and nice values may also be set according to entries in the GECOS field\&.
.PP
On some installations, the environmental variable
\fB$TERM\fR
will be initialized to the terminal type on your tty line, as specified in
/etc/ttytype\&.
.PP
Ein Startskript f\(:ur Ihren Befehlsinterpreter kann auch ausgef\(:uhrt werden\&. F\(:ur weitere Informationen dar\(:uber sehen Sie bitte in den entsprechenden Handbuchseiten nach\&.
.PP
Eine Subsystem\-Anmeldung wird durch einen \(Fc*\(Fo als erstes Zeichen der Anmelde\-Shell gekennzeichnet\&. Das angegebene pers\(:onliche Verzeichnis wird zur Wurzel des Verzeichnisbaumes, in dem der Benutzer tats\(:achlich angemeldet ist\&.
.PP
The
\fBlogin\fR
program is NOT responsible for removing users from the utmp file\&. It is the responsibility of
\fBgetty\fR(8)
and
\fBinit\fR(8)
to clean up apparent ownership of a terminal session\&. If you use
\fBlogin\fR
from the shell prompt without
\fBexec\fR, the user you use will continue to appear to be logged in even after you log out of the "subsession"\&.
.SH "OPTIONEN"
.PP
\fB\-f\fR
.RS 4
Keine Authentifizierung durchf\(:uhren, der Benutzer ist vorauthentifiziert\&.
.sp
Note: In that case,
\fIusername\fR
is mandatory\&.
.RE
.PP
\fB\-h\fR
.RS 4
Name des fernen Rechners f\(:ur diese Anmeldung\&.
.RE
.PP
\fB\-p\fR
.RS 4
beh\(:alt die Umgebung bei\&.
.RE
.PP
\fB\-r\fR
.RS 4
f\(:uhrt das Autologin\-Protokoll f\(:ur
\fBrlogin\fR
aus\&.
.RE
.PP
The
\fB\-r\fR,
\fB\-h\fR
and
\fB\-f\fR
options are only used when
\fBlogin\fR
is invoked by root\&.
.SH "WARNUNGEN"
.PP
This version of
\fBlogin\fR
has many compilation options, only some of which may be in use at any particular site\&.
.PP
Der Ort von Dateien ist von der Konfiguration des Systems abh\(:angig\&.
.PP
The
\fBlogin\fR
program is NOT responsible for removing users from the utmp file\&. It is the responsibility of
\fBgetty\fR(8)
and
\fBinit\fR(8)
to clean up apparent ownership of a terminal session\&. If you use
\fBlogin\fR
from the shell prompt without
\fBexec\fR, the user you use will continue to appear to be logged in even after you log out of the "subsession"\&.
.PP
As with any program,
\fBlogin\fR\*(Aqs 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\&.
.SH "KONFIGURATION"
.PP
The following configuration variables in
/etc/login\&.defs
change the behavior of this tool:
.SH "DATEIEN"
.PP
/var/run/utmp
.RS 4
Liste aktueller Anmeldungen
.RE
.PP
/var/log/wtmp
.RS 4
Liste vorangegangener Anmeldungen
.RE
.PP
/etc/passwd
.RS 4
Informationen zu den Benutzerkonten
.RE
.PP
/etc/shadow
.RS 4
gesch\(:utzte Informationen zu den Benutzerkonten
.RE
.PP
/etc/motd
.RS 4
Datei mit der Systemmeldung des Tages
.RE
.PP
/etc/nologin
.RS 4
existiert diese Datei, kann sich mit Ausnahme des Systemadministrators niemand anmelden\&.
.RE
.PP
/etc/ttytype
.RS 4
Liste der Terminaltypen
.RE
.PP
$HOME/\&.hushlogin
.RS 4
unterdr\(:uckt die Ausgabe von Systemnachrichten nach erfolgreicher Anmeldung
.RE
.PP
/etc/login\&.defs
.RS 4
konfiguriert die Shadow\-Hilfsprogramme\&.
.RE
.SH "SIEHE AUCH"
.PP
\fBmail\fR(1),
\fBpasswd\fR(1),
\fBsh\fR(1),
\fBsu\fR(1),
\fBlogin.defs\fR(5),
\fBnologin\fR(5),
\fBpasswd\fR(5),
\fBsecuretty\fR(5),
\fBgetty\fR(8)\&.
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