path: root/scripts/desc/xdg-mime.xml

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<refentry id="xdg-mime">
  <refentryinfo>
    <title>xdg-mime Manual</title>
    <copyright>
      <year>2006</year>
    </copyright>
    <author>
      <firstname>Kevin</firstname>
      <surname>Krammer</surname>
    </author>
    <address><email>kevin.krammer@gmx.at</email></address>
    <author>
      <firstname>Jeremy</firstname>
      <surname>White</surname>
    </author>
    <address><email>jwhite@codeweavers.com</email></address>
    <releaseinfo>xdg-utils 1.0</releaseinfo>
  </refentryinfo>

  <refmeta>
    <refentrytitle>xdg-mime</refentrytitle>
    <manvolnum>1</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>xdg-mime</refname>
    <refpurpose>command line tool for querying information about file type handling
and adding descriptions for new file types</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>xdg-mime</command>
      <arg choice="plain">query</arg>
      <group choice="req">
	<arg choice="plain">filetype <replaceable>FILE</replaceable></arg>
	<arg choice="plain">default <replaceable>mimetype</replaceable></arg>
      </group>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>xdg-mime</command>
      <arg choice="plain">default</arg>
      <arg choice="plain"><replaceable>application</replaceable></arg>
      <arg choice="plain"><replaceable>mimetype(s)</replaceable></arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>xdg-mime</command>
      <arg choice="plain">install</arg>	
      <arg><option>--mode <replaceable>mode</replaceable></option></arg>
      <arg><option>--novendor</option></arg>
      <arg choice="plain"><replaceable>mimetypes-file</replaceable></arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>xdg-mime</command>
      <arg choice="plain">uninstall</arg>	
      <arg><option>--mode <replaceable>mode</replaceable></option></arg>
      <arg choice="plain"><replaceable>mimetypes-file</replaceable></arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>xdg-mime</command>
      <group choice="req">
        <arg choice="plain"><option>--help</option></arg>
        <arg choice="plain"><option>--manual</option></arg>
        <arg choice="plain"><option>--version</option></arg>
      </group>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id="description">
    <title>Description</title>
    <para>
      The xdg-mime program can be used to query information about file types
      and to add descriptions for new file types.
    </para>
  </refsect1>
  <refsect1 id="commands">
    <title>Commands</title>
    <variablelist>
      <varlistentry>
	<term>query file</term>
	<listitem>
	  <simpara>
	    Returns the file type of <replaceable>FILE</replaceable> in the form of a MIME type.
	  </simpara>
	  <simpara>
		Please note that <replaceable>FILE</replaceable> names starting with a <code>-</code> will be rejected, this can be mitigated:
	  </simpara>
      <itemizedlist>
        <listitem><para>Pass absolute paths, i.e. by using <command>realpath</command> as a preprocessor.</para></listitem>
		<listitem><para>Prefix known relative filepaths with a <quote>./</quote>. For example using <code>sed -E 's|^[^/]|./\0|'</code> as a preprocessor.</para></listitem>
      </itemizedlist>
	  <simpara>
            The <emphasis>query file</emphasis> option is for use inside a desktop session only.
            It is not recommended to use xdg-mime query file as root.
	  </simpara>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term>query default</term>
	<listitem>
	  <simpara>
	    Returns the default application that the desktop environment uses for opening
	    files of type <replaceable>mimetype</replaceable>. The default application is
            identified by its *.desktop file.
	  </simpara>
	  <simpara>
        The value returned by this command may or may not match the application launched by <command>xdg-open</command> as <command>xdg-open</command> hands over to desktop specific openers most of the time which may implement their own logic.
	  </simpara>
	  <simpara>
            The <emphasis>query default</emphasis> option is for use inside a desktop session only.
            It is not recommended to use xdg-mime query default as root.
	  </simpara>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term>default</term>
	<listitem>
	  <simpara>
	    Ask the desktop environment to make <replaceable>application</replaceable>
	    the default application for opening
	    files of type <replaceable>mimetype</replaceable>. An
            application can be made the default for several file types by
            specifying multiple mimetypes.
	  </simpara>
	  <simpara>
	    <replaceable>application</replaceable> is the desktop file
	    id of the application and has the form vendor-name.desktop.
	    <replaceable>application</replaceable> must already be installed
	    in the desktop menu before it can be made the default handler.
	    The application's desktop file must list support for all the
	    MIME types that it wishes to be the default handler for.
	  </simpara>
	  <simpara>
	    Requests to make an application a default handler may be
	    subject to system policy or approval by the end-user. xdg-mime
            query can be used to verify whether an application is the
            actual default handler for a specific file type.   
	  </simpara>
	  <simpara>
        <emphasis>Security Note:</emphasis> Never set a handler that will blindly execute code or commands from the file being handled. Such behaviour will sooner than later lead to unintended code execution i.e. through a curious user trying to inspect a freshly downloaded file but running it by accident.
	  </simpara>
	  <simpara>
        Keeping opening and executing separate actions helps with people protecting themselves from malware, the default handler is an opener, not a runner.
	  </simpara>
	  <simpara>
            The <emphasis>default</emphasis> option is for use inside a desktop session only.
            It is not recommended to use xdg-mime default as root.
	  </simpara>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term>install</term>
	<listitem>
	  <simpara>
	    Adds the file type descriptions provided in <replaceable>mimetypes-file</replaceable>
            to the desktop environment. <replaceable>mimetypes-file</replaceable>
            must be a XML file that follows the freedesktop.org
            Shared MIME-info Database specification
            and that has a mime-info element as its document root. For
            each new file type one or more icons with name
            <replaceable>type</replaceable>-<replaceable>subtype</replaceable>
            must be installed with the <command>xdg-icon-resource</command>
            command in the <emphasis>mimetypes</emphasis> context. For example the
            filetype application/vnd.oasis.opendocument.text requires an
            icon named application-vnd.oasis.opendocument.text
            to be installed (unless the file type recommends another icon name).
	  </simpara>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term>uninstall</term>
	<listitem>
	  <simpara>
	    Removes the file type descriptions provided in <replaceable>mimetypes-file</replaceable>
            and previously added with <command>xdg-mime install</command> from the
            desktop environment. <replaceable>mimetypes-file</replaceable>
            must be a XML file that follows the freedesktop.org
            Shared MIME-info Database specification
            and that has a mime-info element as its document root.
	  </simpara>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id="options">
    <title>Options</title>
    <variablelist>
      <varlistentry>
	<term><option>--mode</option> <replaceable>mode</replaceable></term>
	<listitem>
	  <simpara><replaceable>mode</replaceable> can be
            <emphasis>user</emphasis> or <emphasis>system</emphasis>.
            In user mode the file is (un)installed for the current user
            only. In system mode the file is (un)installed for all users
            on the system. Usually only root is allowed to install in
            system mode.
	  </simpara>
	  <simpara>
	    The default is to use system mode when called by root
	    and to use user mode when called by a non-root user.
	  </simpara>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><option>--novendor</option></term>
	<listitem>
	  <simpara>
	    Normally, xdg-mime checks to ensure that the
	    <replaceable>mimetypes-file</replaceable> to be installed
	    has a proper vendor prefix. This option can be
	    used to disable that check.
	  </simpara>
	  <simpara>
            A vendor prefix consists of alpha characters ([a-zA-Z]) and is
            terminated with a dash ("-").
            Companies and organizations are encouraged to use a word
            or phrase, preferably the organizations name, for which they hold
            a trademark as their vendor prefix.
            The purpose of the vendor prefix is to prevent name conflicts.
          </simpara>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term><option>--help</option></term>
	<listitem>
	  <simpara>
	    Show command synopsis.
	  </simpara>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term><option>--manual</option></term>
	<listitem>
	  <simpara>
	    Show this manual page.
	  </simpara>
	</listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--version</option></term>
        <listitem>
          <simpara>
            Show the xdg-utils version information.
          </simpara>
        </listitem>
      </varlistentry>

    </variablelist>
  </refsect1>
  <refsect1 id="env_vars">
    <title>Environment Variables</title>
    <para>
      xdg-mime honours the following environment variables:
    </para>
    <variablelist>
      <varlistentry>
	<term>XDG_UTILS_DEBUG_LEVEL</term>
	<listitem>
	  <simpara>
	    Setting this environment variable to a non-zero numerical value
	    makes xdg-mime do more verbose reporting on stderr.
	    Setting a higher value increases the verbosity.
	  </simpara>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>XDG_UTILS_INSTALL_MODE</term>
	<listitem>
	  <simpara>
	    This environment variable can be used by the user or
            administrator to override the installation mode.
	    Valid values are <emphasis>user</emphasis> and
            <emphasis>system</emphasis>.  
	  </simpara>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id="exitcodes">
    <title>Exit Codes</title>
    <para>
      An exit code of 0 indicates success while a non-zero exit code
      indicates failure. The following failure codes can be returned:
    </para>
    <variablelist>
      <varlistentry>
	<term><option>1</option></term>
	<listitem>
	  <simpara>
	    Error in command line syntax.
	  </simpara>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><option>2</option></term>
	<listitem>
	  <simpara>
	    One of the files passed on the command line did not exist.
	  </simpara>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><option>3</option></term>
	<listitem>
	  <simpara>
	    A required tool could not be found. 
	  </simpara>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><option>4</option></term>
	<listitem>
	  <simpara>
	    The action failed. 
	  </simpara>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><option>5</option></term>
	<listitem>
	  <simpara>
	    No permission to read one of the files passed on the command
            line.
	  </simpara>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>
  <refsect1 id="seealso">
    <title>See Also</title>
    <para><citerefentry><refentrytitle>xdg-icon-resource</refentrytitle>
        <manvolnum>1</manvolnum>
      </citerefentry>,
      <citerefentry><refentrytitle>xdg-desktop-menu</refentrytitle>
        <manvolnum>1</manvolnum>
      </citerefentry>,
      <ulink url="http://www.freedesktop.org/wiki/Specifications/shared-mime-info-spec/">Shared MIME database specification</ulink>,
      <ulink url="http://www.freedesktop.org/wiki/Specifications/mime-apps-spec/">MIME applications associations specification</ulink>
    </para>
  </refsect1>
  <refsect1 id="examples">
    <title>Examples</title>
    <para>
<programlisting>
xdg-mime query filetype /tmp/foobar.png
</programlisting>Prints the MIME type of the file /tmp/foobar.png, in this
case image/png
    </para>
    <para>
<programlisting>
xdg-mime query default image/png
</programlisting>Prints the .desktop filename of the application which is
      registered to open PNG files.
    </para>
    <para>
<programlisting>
xdg-mime install shinythings-shiny.xml
</programlisting>Adds a file type description for "shiny"-files.
      "shinythings-" is used as the vendor prefix.
      The file type description could look as follows.  
<programlisting>
shinythings-shiny.xml:

&lt;?xml version="1.0"?&gt;
&lt;mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'&gt;
  &lt;mime-type type="text/x-shiny"&gt;
    &lt;comment&gt;Shiny new file type&lt;/comment&gt;
    &lt;glob pattern="*.shiny"/&gt;
    &lt;glob pattern="*.shi"/&gt;
  &lt;/mime-type&gt;
&lt;/mime-info&gt;
</programlisting>An icon for this new file type must also be installed, for
example with:
<programlisting>
xdg-icon-resource install --context mimetypes --size 64 shiny-file-icon.png text-x-shiny
</programlisting>
    </para>
  </refsect1>
</refentry>