man/systemd-ask-password.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
   5 <!--
   6   This file is part of systemd.
   7
   8   Copyright 2011 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 -->
  23
  24 <refentry id="systemd-ask-password"
  25           xmlns:xi="http://www.w3.org/2001/XInclude">
  26
  27         <refentryinfo>
  28                 <title>systemd-ask-password</title>
  29                 <productname>systemd</productname>
  30
  31                 <authorgroup>
  32                         <author>
  33                                 <contrib>Developer</contrib>
  34                                 <firstname>Lennart</firstname>
  35                                 <surname>Poettering</surname>
  36                                 <email>lennart@poettering.net</email>
  37                         </author>
  38                 </authorgroup>
  39         </refentryinfo>
  40
  41         <refmeta>
  42                 <refentrytitle>systemd-ask-password</refentrytitle>
  43                 <manvolnum>1</manvolnum>
  44         </refmeta>
  45
  46         <refnamediv>
  47                 <refname>systemd-ask-password</refname>
  48                 <refpurpose>Query the user for a system password</refpurpose>
  49         </refnamediv>
  50
  51         <refsynopsisdiv>
  52                 <cmdsynopsis>
  53                         <command>systemd-ask-password <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt">MESSAGE</arg></command>
  54                 </cmdsynopsis>
  55         </refsynopsisdiv>
  56
  57         <refsect1>
  58                 <title>Description</title>
  59
  60                 <para><command>systemd-ask-password</command> may be
  61                 used to query a system password or passphrase from the
  62                 user, using a question message specified on the
  63                 command line. When run from a TTY it will query a
  64                 password on the TTY and print it to standard output. When run
  65                 with no TTY or with <option>--no-tty</option> it will
  66                 query the password system-wide and allow active users
  67                 to respond via several agents. The latter is
  68                 only available to privileged processes.</para>
  69
  70                 <para>The purpose of this tool is to query system-wide
  71                 passwords -- that is passwords not attached to a
  72                 specific user account. Examples include: unlocking
  73                 encrypted hard disks when they are plugged in or at
  74                 boot, entering an SSL certificate passphrase for web
  75                 and VPN servers.</para>
  76
  77                 <para>Existing agents are: a boot-time password agent
  78                 asking the user for passwords using Plymouth; a
  79                 boot-time password agent querying the user directly on
  80                 the console; an agent requesting password input via a
  81                 <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  82                 message; an agent suitable for running in a GNOME
  83                 session; a command line agent which can be started
  84                 temporarily to process queued password requests; a TTY
  85                 agent that is temporarily spawned during
  86                 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  87                 invocations.</para>
  88
  89                 <para>Additional password agents may be implemented
  90                 according to the <ulink
  91                 url="http://www.freedesktop.org/wiki/Software/systemd/PasswordAgents">systemd
  92                 Password Agent Specification</ulink>.</para>
  93
  94                 <para>If a password is queried on a TTY, the user may
  95                 press TAB to hide the asterisks normally shown for
  96                 each character typed. Pressing Backspace as first key
  97                 achieves the same effect.</para>
  98
  99         </refsect1>
 100
 101         <refsect1>
 102                 <title>Options</title>
 103
 104                 <para>The following options are understood:</para>
 105
 106                 <variablelist>
 107                         <varlistentry>
 108                                 <term><option>--icon=</option></term>
 109
 110                                 <listitem><para>Specify an icon name
 111                                 alongside the password query, which may
 112                                 be used in all agents supporting
 113                                 graphical display. The icon name
 114                                 should follow the <ulink
 115                                 url="http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">XDG
 116                                 Icon Naming
 117                                 Specification</ulink>.</para></listitem>
 118                         </varlistentry>
 119
 120                         <varlistentry>
 121                                 <term><option>--timeout=</option></term>
 122
 123                                 <listitem><para>Specify the query
 124                                 timeout in seconds. Defaults to
 125                                 90s. A timeout of 0 waits indefinitely.
 126                                 </para></listitem>
 127                         </varlistentry>
 128
 129                         <varlistentry>
 130                                 <term><option>--no-tty</option></term>
 131
 132                                 <listitem><para>Never ask for password
 133                                 on current TTY even if one is
 134                                 available. Always use agent
 135                                 system.</para></listitem>
 136                         </varlistentry>
 137
 138                         <varlistentry>
 139                                 <term><option>--accept-cached</option></term>
 140
 141                                 <listitem><para>If passed, accept
 142                                 cached passwords, i.e. passwords
 143                                 previously typed in.</para></listitem>
 144                         </varlistentry>
 145
 146                         <varlistentry>
 147                                 <term><option>--multiple</option></term>
 148
 149                                 <listitem><para>When used in
 150                                 conjunction with
 151                                 <option>--accept-cached</option>
 152                                 accept multiple passwords. This will
 153                                 output one password per
 154                                 line.</para></listitem>
 155                         </varlistentry>
 156
 157                         <xi:include href="standard-options.xml" xpointer="help" />
 158                 </variablelist>
 159
 160         </refsect1>
 161
 162         <refsect1>
 163                 <title>Exit status</title>
 164
 165                 <para>On success, 0 is returned, a non-zero failure
 166                 code otherwise.</para>
 167         </refsect1>
 168
 169         <refsect1>
 170                 <title>See Also</title>
 171                 <para>
 172                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 173                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 174                         <citerefentry><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 175                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 176                 </para>
 177         </refsect1>
 178
 179 </refentry>