source: xincludes/update-icons-and-desktop.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE note PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" >


    <note>
      <para>
        This package installs icon files into the <filename
        class="directory">/usr/share/icons/hicolor</filename> hierarchy and
        desktop files into the <filename
        class="directory">/usr/share/applications</filename> hierarchy. You can
        improve system performance and memory usage by updating
        <filename>/usr/share/icons/hicolor/index.theme</filename> and
        <filename>/usr/share/applications/mimeinfo.cache</filename>. To perform
        the update you must have <xref linkend="gtk3"/> installed (for the icon
        cache) and <xref linkend="desktop-file-utils"/> (for the desktop cache)
        and issue the following commands as the <systemitem
        class="username">root</systemitem> user:
      </para>

<screen role="nodump"><userinput>gtk-update-icon-cache -qtf /usr/share/icons/hicolor &amp;&amp;
update-desktop-database -q</userinput></screen>
    </note>