man/systemd-ask-password.xml

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   8   Copyright 2011 Lennart Poettering
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  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 used to query
  61     a system password or passphrase from the user, using a question
  62     message specified on the command line. When run from a TTY it will
  63     query a password on the TTY and print it to standard output. When
  64     run with no TTY or with <option>--no-tty</option> it will query
  65     the password system-wide and allow active users to respond via
  66     several agents. The latter is only available to privileged
  67     processes.</para>
  68
  69     <para>The purpose of this tool is to query system-wide passwords
  70     -- that is passwords not attached to a specific user account.
  71     Examples include: unlocking encrypted hard disks when they are
  72     plugged in or at boot, entering an SSL certificate passphrase for
  73     web and VPN servers.</para>
  74
  75     <para>Existing agents are: a boot-time password agent asking the
  76     user for passwords using Plymouth; a boot-time password agent
  77     querying the user directly on the console; an agent requesting
  78     password input via a
  79     <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  80     message; an agent suitable for running in a GNOME session; a
  81     command line agent which can be started temporarily to process
  82     queued password requests; a TTY agent that is temporarily spawned
  83     during
  84     <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  85     invocations.</para>
  86
  87     <para>Additional password agents may be implemented according to
  88     the <ulink
  89     url="http://www.freedesktop.org/wiki/Software/systemd/PasswordAgents">systemd
  90     Password Agent Specification</ulink>.</para>
  91
  92     <para>If a password is queried on a TTY, the user may press TAB to
  93     hide the asterisks normally shown for each character typed.
  94     Pressing Backspace as first key achieves the same effect.</para>
  95
  96   </refsect1>
  97
  98   <refsect1>
  99     <title>Options</title>
 100
 101     <para>The following options are understood:</para>
 102
 103     <variablelist>
 104       <varlistentry>
 105         <term><option>--icon=</option></term>
 106
 107         <listitem><para>Specify an icon name alongside the password
 108         query, which may be used in all agents supporting graphical
 109         display. The icon name should follow the <ulink
 110         url="http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">XDG
 111         Icon Naming Specification</ulink>.</para></listitem>
 112       </varlistentry>
 113
 114       <varlistentry>
 115         <term><option>--timeout=</option></term>
 116
 117         <listitem><para>Specify the query timeout in seconds. Defaults
 118         to 90s. A timeout of 0 waits indefinitely. </para></listitem>
 119       </varlistentry>
 120
 121       <varlistentry>
 122         <term><option>--echo</option></term>
 123
 124         <listitem><para>Echo the user input instead of masking it.
 125         This is useful when using
 126         <filename>systemd-ask-password</filename> to query for
 127         usernames. </para></listitem>
 128       </varlistentry>
 129
 130       <varlistentry>
 131         <term><option>--no-tty</option></term>
 132
 133         <listitem><para>Never ask for password on current TTY even if
 134         one is available. Always use agent system.</para></listitem>
 135       </varlistentry>
 136
 137       <varlistentry>
 138         <term><option>--accept-cached</option></term>
 139
 140         <listitem><para>If passed, accept cached passwords, i.e.
 141         passwords previously typed in.</para></listitem>
 142       </varlistentry>
 143
 144       <varlistentry>
 145         <term><option>--multiple</option></term>
 146
 147         <listitem><para>When used in conjunction with
 148         <option>--accept-cached</option> accept multiple passwords.
 149         This will output one password per line.</para></listitem>
 150       </varlistentry>
 151
 152       <xi:include href="standard-options.xml" xpointer="help" />
 153     </variablelist>
 154
 155   </refsect1>
 156
 157   <refsect1>
 158     <title>Exit status</title>
 159
 160     <para>On success, 0 is returned, a non-zero failure code
 161     otherwise.</para>
 162   </refsect1>
 163
 164   <refsect1>
 165     <title>See Also</title>
 166     <para>
 167       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 168       <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 169       <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 170       <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 171     </para>
 172   </refsect1>
 173
 174 </refentry>