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diff --git a/man/systemd-id128.xml b/man/systemd-id128.xml new file mode 100644 index 0000000..d9378b6 --- /dev/null +++ b/man/systemd-id128.xml @@ -0,0 +1,211 @@ +<?xml version='1.0'?> <!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- SPDX-License-Identifier: LGPL-2.1-or-later --> + +<refentry id="systemd-id128" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>systemd-id128</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd-id128</refentrytitle> + <manvolnum>1</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-id128</refname> + <refpurpose>Generate and print sd-128 identifiers</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <cmdsynopsis> + <command>systemd-id128</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <arg choice="plain">new</arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-id128</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <arg choice="plain">machine-id</arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-id128</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <arg choice="plain">boot-id</arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-id128</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <arg choice="plain">invocation-id</arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-id128</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <arg choice="plain">show</arg> + <arg choice="opt" rep="repeat">NAME|UUID</arg> + </cmdsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><command>id128</command> may be used to conveniently print + <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry> + UUIDs. What identifier is printed depends on the specific verb.</para> + + <para>With <command>new</command>, a new random identifier will be generated.</para> + + <para>With <command>machine-id</command>, the identifier of the current machine will be + printed. See + <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para> + + <para>With <command>boot-id</command>, the identifier of the current boot will be + printed.</para> + + <para>With <command>invocation-id</command>, the identifier of the current service invocation + will be printed. This is available in systemd services. See + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + </para> + + <para>With <command>show</command>, well-known IDs are printed (for now, only GPT partition type UUIDs), + along with brief identifier strings. When no arguments are specified, all known IDs are shown. When + arguments are specified, they may be the identifiers or ID values of one or more known IDs, which are + then printed with their name, or arbitrary IDs, which are then printed with a placeholder name. Combine + with <option>--uuid</option> to list the IDs in UUID style, i.e. the way GPT partition type UUIDs are + usually shown.</para> + + <para><command>machine-id</command>, <command>boot-id</command>, and <command>show</command> may be + combined with the <option>--app-specific=<replaceable>app-id</replaceable></option> switch to generate + application-specific IDs. See + <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for the discussion when this is useful. Support for <command>show --app-specific=</command> was added in + version 255.</para> + </refsect1> + + <refsect1> + <title>Options</title> + + <para>The following options are understood:</para> + + <variablelist> + <varlistentry> + <term><option>-p</option></term> + <term><option>--pretty</option></term> + + <listitem><para>Generate output as programming language snippets.</para> + + <xi:include href="version-info.xml" xpointer="v240"/></listitem> + </varlistentry> + + <varlistentry> + <term><option>-P</option></term> + <term><option>--value</option></term> + + <listitem><para>Only print the value. May be combined with + <option>-u</option>/<option>--uuid</option>.</para> + + <xi:include href="version-info.xml" xpointer="v255"/></listitem> + </varlistentry> + + <varlistentry> + <term><option>-a <replaceable>app-id</replaceable></option></term> + <term><option>--app-specific=<replaceable>app-id</replaceable></option></term> + + <listitem><para>With this option, identifiers will be printed that are the result of hashing the + application identifier <replaceable>app-id</replaceable> and another ID. The + <replaceable>app-id</replaceable> argument must be a valid sd-id128 string identifying the + application. When used with <command>machine-id</command>, the other ID will be the machine ID as + described in + <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>, when + used with <command>boot-id</command>, the other ID will be the boot ID, and when used with + <command>show</command>, the other ID or IDs should be specified via the positional arguments.</para> + + <xi:include href="version-info.xml" xpointer="v240"/> + </listitem> + </varlistentry> + + <varlistentry> + <term><option>-u</option></term> + <term><option>--uuid</option></term> + + <listitem><para>Generate output as a UUID formatted in the "canonical representation", with five + groups of digits separated by hyphens. See the Wikipedia entry for + <ulink url="https://en.wikipedia.org/wiki/Universally_unique_identifier#Format">Universally Unique Identifiers</ulink> + for more discussion.</para> + + <xi:include href="version-info.xml" xpointer="v244"/></listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + <xi:include href="standard-options.xml" xpointer="version" /> + </variablelist> + </refsect1> + + <refsect1> + <title>Exit status</title> + + <para>On success 0 is returned, and a non-zero failure code otherwise.</para> + </refsect1> + + <refsect1> + <title>Examples</title> + + <example> + <title>Show a well-known UUID</title> + <programlisting> +$ systemd-id128 show --value user-home +773f91ef66d449b5bd83d683bf40ad16 + +$ systemd-id128 show --value --uuid user-home +773f91ef-66d4-49b5-bd83-d683bf40ad16 + +$ systemd-id128 show 773f91ef-66d4-49b5-bd83-d683bf40ad16 +NAME ID +user-home 773f91ef66d449b5bd83d683bf40ad16 + </programlisting> + </example> + + <example> + <title>Generate an application-specific UUID</title> + + <programlisting> +$ systemd-id128 machine-id -u +3a9d668b-4db7-4939-8a4a-5e78a03bffb7 + +$ systemd-id128 new -u +1fb8f24b-02df-458d-9659-cc8ace68e28a + +$ systemd-id128 machine-id -u -a 1fb8f24b-02df-458d-9659-cc8ace68e28a +47b82cb1-5339-43da-b2a6-1c350aef1bd1 + +$ systemd-id128 -Pu show 3a9d668b-4db7-4939-8a4a-5e78a03bffb7 \ + -a 1fb8f24b-02df-458d-9659-cc8ace68e28a +47b82cb1-5339-43da-b2a6-1c350aef1bd1 + </programlisting> + + <para>On a given machine with the ID 3a9d668b-4db7-4939-8a4a-5e78a03bffb7, for the application + 1fb8f24b-02df-458d-9659-cc8ace68e28a, we generate an application-specific machine ID + (47b82cb1-5339-43da-b2a6-1c350aef1bd1). If we want to later recreate the same calculation on a + different machine, we need to specify both IDs explicitly as parameters to <command>show</command>. + </para> + </example> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |