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<!DOCTYPE BOOK PUBLIC "-//FreeBSD//DTD DocBook V4.1-Based Extension//EN" [
<!ENTITY RCL "<application>Recoll</application>">
<!ENTITY XAP "<application>Xapian</application>">

]>
 
<book lang="en">
  
  <bookinfo>
    <title>Recoll user manual</title>


    <author>
      <firstname>Jean-Francois</firstname>
      <surname>Dockes</surname>
      <affiliation>
        <address><email>jean-francois.dockes@wanadoo.fr</email></address>
      </affiliation>
    </author>

    <copyright>
      <year>2005</year>
      <holder role="mailto:jean-francois.dockes@wanadoo.fr">Jean-Francois
      Dockes</holder>
    </copyright>

    <releaseinfo>$Id: usermanual.sgml,v 1.4 2006-01-19 12:01:42 dockes Exp $</releaseinfo>

    <abstract>
      <para>This document introduces full text search notions
      and describes the installation and use of the &RCL; application.</para>
    </abstract>


  </bookinfo>
  
  <chapter id="rcl.introduction">
    <title>Introduction</title>

    <sect1 id="rcl.introduction.tryit">
      <title>Giving it a try</title>

      <para>If you do not like reading manuals (who does?) and would
      like to give &RCL; a try, just perform <link
      linkend="rcl.install">installation</link> and start the
      <command>recoll</command> user interface, which will index your
      home directory and let you search it right after.</para>

      <para>Do not do this if your home has a huge
      number of documents and you do not want to wait or are very
      short on disk space. In this case, you may want to edit the <link
      linkend="rcl.indexing.config">configuration file</link> first to
      restrict the indexed area.</para>

      <para>Also be aware that you will need to install the
      appropriate supporting applications for document types that need
      them (for example <application>antiword</application> for
      ms-word files), and that the default character set used to read
      raw text files for indexing is iso8859-1, which may not be
      appropriate for you.</para>
      
    <sect1 id="rcl.introduction.search"> 
      <title>Full text search</title>

      <para>&RCL; is a full text search application. Full text search
        applications let you find your data by content rather
        than by external attributes (like a file name). More
        specifically, they will let you specify words (terms) that
        should or should not appear in the text you are looking for,
        and return a list of matching documents, ordered so that the
        most <emphasis>relevant</emphasis> documents will appear
        first.</para>

      <para>You do not need to remember in what file or email message you
        stored a given piece of information. You just ask for related
        terms, and the tool will return a list of documents where
        those terms are prominent.</para>

      <para>This mode of operation has been made very familiar by www
       search engines.</para>

      <para>The notion of relevance is a difficult one, as only you, the
      user, actually know which documents are relevant to your search,
      and the application can only try a guess. The quality of this
      guess is probably the most important element for a search
      application.</para> 

      <para>In many cases, you are looking for all the forms of a
        word, not for a specific form or spelling. These different
        forms may include plurals, different tenses for a verb, or
        terms derived from the same root or <emphasis>stem</emphasis>
        (exemple: floor, floors, floored, floorings...). &RCL; will by
        default expand queries to all such related terms (words that
        reduce to the same stem). This expansion can be disabled at
        search time.</para>

     <para>Stemming, by itself, does not provide for misspellings or
        phonetic searches. &RCL; currently does not support these.</para>


    </sect1>

      <sect1 id="rcl.introduction.recoll">
      <title>Recoll overview</title>

      <para>&RCL; uses the 
      <ulink url="http://www.xapian.org">&XAP;</ulink> information retrieval
      library as its storage and retrieval engine. &XAP; is a very
      mature package using <ulink
      url="http://www.xapian.org/docs/intro_ir.html">a sophisticated
      probabilistic ranking model</ulink>. &RCL; provides the interface
      to get data into (indexation) and out (searching) of the system.</para>

      <para>In practice, &XAP; works by remembering where terms appear
      in your document files. The acquisition process is called
      indexation. </para> 

      <para>The resulting database can be big (roughly the size of the
        original document set), but it  is not a document archive. &RCL;
        can only display documents that still exist at the place from which
        they were indexed.</para>

      <para>&RCL; stores all internal data in <application>Unicode
      UTF-8</application> format, and it can index files with
      different character sets, encodings, and languages into the same
      database. It has input filters for many document types.</para>
      
      <para>Stemming depends on the document language. &RCL; stores
      the unstemmed versions of terms and uses auxiliary databases for
      term expansion. It can switch stemming languages, or add a
      language, without reindexing.  Storing documents in different
      languages in the same database is possible, and useful in
      practice, but does introduce possibilities of confusion. &RCL;
      makes no attempt at automatic language recognition.</para>

      <para>&RCL; has many parameters which define exactly what to
        index, and how to classify and decode the source
        documents. These are kept in a <link
        linkend="rcl.indexing.config">configuration file</link>. A
        sample configuration is installed into the
        <filename>.recoll</filename> subdirectory of your home
        directory when you first execute a &RCL; command. The initial
        configuration will index your home directory with default
        parameters and should be sufficient for giving &RCL; a try,
        but you may want to adjust it later.</para>

      <para><link linkend="rcl.indexing.exec">Indexation</link> is started
      automatically the first time you execute the
      <command>recoll</command> search graphical user interface, or by
      executing the <command>recollindex</command> command.</para>

      <para><link linkend="rcl.search">Searches</link> are
      performed inside the <command>recoll</command> 
      program, which has many options to help you find what you are
      looking for.</para> 

    </sect1>
  </chapter>


  <chapter id="rcl.indexing">
    <title>Indexation</title>

    <sect1 id="rcl.indexing.introduction">
      <title>Introduction</title>

      <para>Indexation is the process by which the set of documents is
      analyzed and the data entered into the database. &RCL; indexation
      is normally incremental: documents will only be processed if
      they have been modified. On the first execution, of course, all
      documents will need processing. A full index build can be forced
      later on by specifying an option to the indexation command
      (<command>recollindex -z</command>).</para> 

      <para>&RCL; indexation takes place at discrete times. There is
      currently no interface to real time file modification
      monitors. The typical usage is to have a nightly indexation run
      <link linkend="rcl.indexing.automat">programmed</link> into your
      <command>cron</command> file.</para> 

      <para>&RCL; knows about quite a few different document
      types. The parameters for document types recognition and
      processing are set in 
       <link linkend="rcl.indexing.config">configuration files</link>
      Most file types, like HTML or word processing files, only hold
      one document. Some file types, like mail folder files can hold
      many individually indexed documents.
      </para>

      <para>&RCL; indexation processes plain text, HTML, openoffice
      and e-mail files internally. Other types (ie: postscript, pdf,
      ms-word, rtf) need external applications for preprocessing. The
      list is in the <link
      linkend="rcl.install.building.prereqs">installation</link>
      section.</para>

      <para>Without further configuration, &RCL; will index all
      appropriate files from your home directory, with a reasonable
      set of defaults, if you live in western Europe or the USA. If
      your normal character set is not iso8859-1, you almost certainly
      need to adjust the configuration.</para>

    </sect1>

    <sect1 id="rcl.indexing.config">
      <title>The indexation configuration</title>

      <para>The main configuration file is named 
        <filename>$HOME/.recoll/recoll.conf</filename> by default or
        <filename>$RECOLL_CONFDIR/recoll.conf</filename> if
          RECOLL_CONFDIR is set.</para>

      <para>The most accurate documentation for editing the file is
      given by comments inside the default file that will be created
      when you first start <command>recoll</command>. If you want to
      adjust the configuration before indexation, just click
      <guilabel>Cancel</guilabel> when the program asks if it should
      start initial indexation.</para>

      <para>The configuration is also documented inside the <link
      linkend="rcl.install.config.recollconf">installation chapter</link> of
      this document, or in the recoll.conf(5) man page.</para>

    </sect1>

    <sect1 id="rcl.indexing.exec">
      <title>Starting indexation</title>

      <para>Indexation is performed either by the
        <command>recollindex</command> program, or by the
        indexation thread inside the <command>recoll</command>
        program (use the <guimenu>File</guimenu> menu). 

      <para>If the <command>recoll</command> program finds no database
      when it starts, it will automatically start indexation (except
      if cancelled).</para>

      <para>It is best to avoid interrupting the indexation process, as
        this may sometimes leave the database in a bad state.  This is
        not a serious problem, as you then just need to clear
        everything and restart the indexation: the database files are
        normally stored in the <filename>$HOME/.recoll/xapiandb</filename>
        directory, 
        which you can just delete if needed. Alternatively, you can
        start <command>recollindex -z</command>, which will
        reset the database before indexation.</para>

    </sect1>

    <sect1 id="rcl.indexing.automat">
      <title>Using <command>cron</command> to automate
      indexation</title>

      <para>The most common way to set up indexation is to have a cron
      task execute it every night. For example the following
      <filename>crontab</filename> entry would do it every day at
      3:30AM (supposing <command>recollindex</command> is in your PATH):</para>

      <programlisting>30 3 * * * recollindex > /tmp/recolltrace 2>&1</programlisting>

      <para>The usual command to edit your
      <filename>crontab</filename> is 
        <userinput>crontab -e</userinput> (which will usually start the
      <command>vi</command> editor to edit the file). You may have
      more sophisticated tools available on your system.</para>

    </sect1>

  </chapter>

  <chapter id="rcl.search">
    <title>Search</title>

    <para>The <command>recoll</command> program provides the user
    interface for searching. It is based on the
    <application>QT</application> library.</para>

    <sect1 id="rcl.search.simple">
      <title>Simple search</title>

      <para>Start the <command>recoll</command> program, then
        enter search term(s) in the text field at the top left of the
        window. Clicking the <guilabel>Search</guilabel> button or
        hitting the <keycap>Enter</keycap> key will start a search. By
        default, this will look for documents with any of the terms
        (the ones with more terms will get better scores). You can
        check the <guilabel>All terms</guilabel> checkbox to ensure
        that only documents with all the terms will be returned. Use
        the <guilabel>Tools</guilabel> / <guilabel>Advanced
        search</guilabel> dialog for more complex searches.</para>

      <para>After starting a search, a list of results will instantly
      be displayed in the main list window. Clicking on an entry will
      open an internal preview window for the
      document. Double-clicking will attempt to start an external
      viewer (have a look at the
      <filename>~/.recoll/mimeconf</filename> file to see how these
      are configured).</para>

      <para>By default, the document list is presented in order of
      relevance (how well the system estimates that the document
      matches the query). You can specify a different ordering by
      using the  <link linkend="rcl.search.sort"><guilabel>Tools</guilabel>
        / <guilabel>Sort parameters</guilabel></link> dialog.</para>

    </sect1>

      <sect1 id="rcl.search.complex">
      <title>Complex/advanced search</title>

      <para>The advanced search dialog has fields that will allow a more
        refined search, looking for documents with all given words, a
        given exact phrase, or none of the given words (all fields may
        be combined by an implicit AND clause).</para>

      <para>It will let you search for documents of specific mime
        types (ie: only <literal>text/plain</literal>, or
        <literal>text/html</literal> or
        <literal>application/pdf</literal> etc...)</para>

      <para>It will let you restrict the search results to a subtree of
        the indexed area.</para>

      <para>Click on the <guilabel>Start Search</guilabel> button in
      the advanced search dialog to start the search. The button in
      the main window always performs a simple search.</para>

    </sect1>

    <sect1 id="rcl.search.history">
      <title>Document history</title>

      <para>Documents that you actually view (with the internal preview
        or an external tool) are entered into the document history,
        which is remembered. You can display the history list by using
        the <guilabel>Tools/</guilabel><guilabel>Doc History</guilabel> menu
        entry.</para> 

    </sect1>

    <sect1 id="rcl.search.sort">
      <title>Result list sorting</title>

      <para>The documents in a result list are normally sorted in
      order of relevance. It is possible to specify different sort
      parameters by using the <guimenu>Sort parameters</guimenu>
      dialog (located in the <guimenu>Tools</guimenu>
      menu).</para>

      <para>The tool sorts a specified number of the most
      relevant documents in the result list, according to
      specified criteria. The currently available criteria are
      <emphasis>date</emphasis> and <emphasis>mime type</emphasis>.</para> 

      <para>The sort parameters stay in effect until they are explicitely
      reset, or the program exits.</para>

    </sect1>

    <sect1 id="rcl.search.tips">
      <title>Search tips, shortcuts</title>

      <formalpara><title>Disabling stem expansion</title>
      <para>Entering a capitalized word in any search field will prevent
        stem expansion (no search for
        <literal>gardening</literal> if you enter
        <literal>Garden</literal> instead of
        <literal>garden</literal>). This is the only case where
        character case should make a difference for a &RCL;
        search.</para>
      </formalpara>

      <formalpara><title>Phrases</title>
      <para>A phrase can be looked for by enclosing it in double
        quotes. Example: <literal>"user manual"</literal> will look
        only for occurrences of <literal>user</literal> immediately
        followed by <literal>manual</literal>. You can use the
        <guilabel>This exact phrase</guilabel> field of the advanced
        search dialog to the same effect.</para>
      </formalpara>

      <formalpara><title>Query explanation</title>
	<para>You can get an exact description of what the query
	looked for, including stem expansion, and boolean operators
	used, by clicking on the result list header.</para>
      </formalpara>

      <formalpara><title>Quitting</title>
      <para>Entering <keycap>^Q</keycap> almost anywhere will
        close the application.</para>
      </formalpara>
      <formalpara><title>Closing previews</title>
      <para>Entering <keycap>^W</keycap> in a preview tab will
        close it (and, for the last tab, close the preview
        window).</para>
      </formalpara>
    </sect1>

    <sect1 id="rcl.search.custom">
      <title>Customising the search interface</title>

      <para>It is possible to customise some aspects of the search
      interface by using <guimenu>Query configuration</guimenu> entry
      in the <guimenu>Preferences</guimenu> menu.</para>

      <para>There are two tabs in the dialog, to modify the appearance
      of the user interface (result list appearance), or the
      parameters used for searching (language used for stem
      expansion).</para> 

      <para>The stemming language can be chosen among those that were
      specified in the configuration file, or later added with
      <command>recollindex -s</command> (See the recollindex
      manual). Stemming languages which are dynamically added will be
      deleted at the next indexation pass unless they are also added in
      the configuration file.</para>

    </sect1>

  </chapter>


  <chapter id="rcl.install">
    <title>Installation</title>

      <sect1 id="rcl.install.building">
      <title>Building from source</title>

      <sect2 id="rcl.install.building.prereqs">
	<title>Prerequisites</title>

      <para>At the very least, you will need to download and install the
	<ulink url="http://www.xapian.org">xapian core
	package</ulink> (&RCL; currently uses version 0.9.2), and the <ulink
	url="http://www.trolltech.com/products/qt/index.html">qt
	  runtime and development packages</ulink> (&RCL; currently uses
	version 3.3.3).</para>

      <para>You will most probably be able to find a binary package for
	<application>qt</application> for your system. You may have to
	compile <application>Xapian</application>, 
	but this is not difficult (if you are using
	<application>FreeBSD</application>, there is a port).</para>

      <para>You may also need 
	<ulink
	url="http://www.gnu.org/software/libiconv/">libiconv</ulink>. &RCL;
	currently uses version 1.9 (this should not be critical). On
	<application>Linux</application> systems, the iconv interface
	is part of libc and you should not need to do anything
	special.</para>
      
      <formalpara><title>External file types</title><para>&RCL; uses
      external applications 
	to index some file types. You need to install them for the
	file types that you wish to have indexed:</para>
	</formalpara>

      <itemizedlist>

	<listitem><para>MS Word: <ulink
	url="http://www.winfield.demon.nl"> 
	    antiword</ulink>.</para>
	  </listitem>

	<listitem><para>PDF: pdftotext is part of the <ulink
	    url="http://www.foolabs.com/xpdf/">Xpdf</ulink> package.</para>
	  </listitem>

	<listitem><para>Postscript: <ulink
	  url="http://www.cs.wisc.edu/~ghost/doc/pstotext.htm">
	    pstotext</ulink>.</para>
	  </listitem>

	<listitem>
	    <para>RTF: <ulink
	    url="http://www.gnu.org/software/unrtf/unrtf.html">unrtf</ulink>
          </para>
	  </listitem>
	  
	</itemizedlist>

      <sect2 id="rcl.install.building.build">
	<title>Building</title>

      <para>&RCL; has been built on
	Linux (redhat7.3, mandriva 2005, Fedora Core 3), FreeBSD and
	Solaris 8. If you build on another system, <ulink
	url="mailto:jean-francois.dockes@wanadoo.fr">I would very much
	welcome patches</ulink>.</para>

      <para>Depending on the <application>qt</application>
      configuration on your system, you may have to set the
      <literal>QTDIR</literal> and <literal>QMAKESPECS</literal>
      variables in your environment:</para>
	<itemizedlist>
	  <listitem><para><literal>QTDIR</literal> should point to the
	  directory above the one that holds the qt include files (ie:
	  qt.h).</para>
	  </listitem>
	  <listitem><para><literal>QMAKESPECS</literal> should
	  be set to the name of one of the
	  <application>qt</application> mkspecs subdirectories (ie:
	  linux-g++).</para> 
	  </listitem>
	</itemizedlist>

	<para>On many Linux systems, <literal>QTDIR</literal> is set
	by the login scripts, and <literal>QMAKESPECS</literal> is not
	needed because there is a <filename>default</filename> link in
	<filename>mkspecs/</filename>.</para>

	<para>The &RCL; <command>configure</command> script does a
	better job of checking these variables after release
	1.1.1. Before this, unexplained errors will occur during
	compilation if the environment is not set up. Also, for 1.1.0 the
	<command>qmake</command> command should be in your PATH (later
	releases can also find it in
	<filename>$QTDIR/bin</filename>).</para> 

      <para>Normal procedure:</para>
      <screen>
        <userinput>cd recoll-xxx</userinput>
        <userinput>configure</userinput>
        <userinput>make</userinput>
        <userinput>(practises usual hardship-repelling invocations)</userinput>
      </screen>


      <para>There little autoconfiguration. The
	<command>configure</command> script will mainly link one of
	the system-specific files in the <filename>mk</filename>
	directory to <filename>mk/sysconf</filename>. If your system
	is not known yet, it will tell you as much, and you may want
	to manually copy and modify one of the existing files (the new
	file name should be the output of <command>uname -s</command>).</para>
      </sect2>

      <sect2 id="rcl.install.building.install">
	<title>Installation</title>
      
      <para>Either type <userinput>make install</userinput> or execute
      <userinput>recollinstall targetdir</userinput>, in the root
	of the source tree. This will copy the commands to
	<filename>$targetdir/bin</filename> and the sample
	configuration files, scripts and other shared data to 
	<filename>$targetdir/share/recoll</filename>.</para>
      </sect2>
    </sect1>

    <sect1 id="rcl.install.binary">
      <title>Installing a prebuilt copy</title>

      <sect2 id="rcl.install.binary.package">
	<title>Installing through a package system</title>

	<para>If you are lucky enough to be using a port system or a
	prebuilt package (RPM or other), just follow the usual
	procedure, and have a look at the <link
	linkend="rcl.install.config">configuration
	section</link>.</para>
      </sect2>

      <sect2 id="rcl.install.binary.rcl">
	<title>Installing a prebuilt &RCL;</title>

      <para>The unpackaged binary versions are just compressed tar
      files of a build
	tree, where only the useful parts were kept (executables and
	sample configuration).</para>

      <para>The executable binary files are built with a static link to
	libxapian and libiconv, to make installation easier (no
	dependencies). However, this also means that you cannot change
	the versions which are used.</para> 

      <para>After extracting the tar file, you can proceed with
	<link
	linkend="rcl.install.building.install">installation</link> as
	if you had built the package from source.</para> 
      </sect2>
    </sect1>

    <sect1 id="rcl.install.config">
      <title>Configuration overview</title>

      <para>The personal configuration files and the database are
        normally kept in
	the <filename>.recoll</filename> directory in your home (this
	can be changed with the <literal>RECOLL_CONFDIR</literal>
	environment variable, and a parameter inside the main
	configuration file). If this directory does not exist when
	  <command>recoll</command> or 
	<command>recollindex</command> are started, the
	directory will be created and the sample configuration files will
	be copied. <command>recoll</command> will give you a
	chance to edit the configuration file before starting
	indexation. <command>recollindex</command> will
	proceed immediately.</para>
      
      <para>Most of the parameters specific to the
 	 <command>recoll</command> GUI are set through the
	  <guilabel>Preferences</guilabel> menu and stored in the
	  standard QT place
	  (<filename>$HOME/.qt/recollrc</filename>). You probably do not
	  want to edit this by hand.</para>

      <para>For other options, &RCL; uses text configuration
        files. You will have to edit them by hand for 
	now (there is still some hope for a GUI configuration tool
	in the future). The most accurate documentation for the
	configuration parameters is given by comments inside the sample
	files, and we will just give a general overview here.</para>

	<para>All configuration files share the same format. For
	exemple, a short extract of the main configuration file might
	look as follows:</para> 
	<programlisting>
        # Space-separated list of directories to index.
        topdirs =  ~/docs /usr/share/doc

        [~/somedirectory-with-utf8-txt-files]
        defaultcharset = utf-8
        </programlisting>

	<para>There are three kinds of lines: </para>
	<itemizedlist>
	  <listitem><para>Comment (starts with
	  <emphasis>#</emphasis>) or empty.</para> 
	  </listitem>
	  <listitem><para>Parameter affectation (<emphasis>name =
	  value</emphasis>).</para> 
	  </listitem>
	  <listitem><para>Section definition
	  ([<emphasis>somedirname</emphasis>]).</para> 
	  </listitem>
	</itemizedlist>

	<para>Section lines allow redefining some parameters for a
	directory subtree. Some of the parameters used for indexation
	are looked up hierarchically from the more to the less
	specific. Not all parameters can be meaningfully redefined,
	this is specified for each in the next section. </para>

	<para>The tilde character (~) is expanded in file names to the
	name of the user's home directory.</para>
	
	<para>White space is used for separation inside  lists.
        Elements with embedded spaces can be quoted using
        double-quotes.</para>

      <sect2 id="rcl.install.config.recollconf">
	<title>Main configuration file</title>

	<para><filename>~/.recoll/recoll.conf</filename> is the main
         configuration file. It defines things like
	 what to index (top directories and things to ignore), and the
	 default character set to use for document types which do not
	 specify it internally. </para>

	<para>The default configuration will index your home
	 directory. If this is not appropriate, use 
	 <command>recoll</command> to copy the sample
	 configuration, click <guimenu>Cancel</guimenu>, and edit
	 the configuration file before restarting the command. This
	 will start the initial indexation, which may take some time.</para>
	
	<para>Paramers:</para>

	<variablelist>

	  <varlistentry><term><literal>topdirs</literal></term>
	    <listitem><para>Specifies the list of directories to index
	    (recursively).</para>
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>skippedNames</literal></term>
	    <listitem>
	      <para>A space-separated list of patterns for
	       names of files or directories that should be completely
	       ignored. The list defined in the default file is: </para>
<programlisting>
*~ #* bin CVS  Cache caughtspam  tmp
</programlisting>
	      <para>The list can be redefined for subdirectories, but is only
               actually changed for the top level ones in
               <literal>topdirs</literal>.</para>
	       <para>The top-level directories are not affected by this
	        list (that is, a directory in <literal>topdirs</literal>
	        might match and would still be indexed).</para>
	        <para>The list in the default configuration does not
	        exclude hidden directories (names beginning with a
	        dot), which means that it may index quite a few things
	        that you do not want. On the other hand, mail user
	        agents like <application>thunderbird</application>
	        usually store messages in hidden directories, and you
	        probably want this indexed. One possible solution is to
	        have <userinput>.*</userinput> in
	        <literal>skippedNames</literal>, and add things like
	        <filename>~/.thunderbird</filename> or
	        <filename>~/.evolution</filename> in
	        <literal>topdirs</literal>.</para> 
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>loglevel</literal></term>
	    <listitem><para>Verbosity level for recoll and
	    recollindex. A value of 4 lists quite a lot of
	    debug/information messages. 2 only lists errors. </para>
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>logfilename</literal></term>
	    <listitem><para>Where should the messages go. 'stderr' can
	    be used as a special value. </para>
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>filtersdir</literal></term>
	    <listitem><para>A directory to search for the external
	    filter scripts used to index some types of files. The
	    value should not be changed, except if you want to modify
	    one of the default scripts. The value can be redefined for
	    any subdirectory. </para>
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>indexstemminglanguages</literal></term>
	    <listitem><para>A list of languages for which the stem
	    expansion databases will be built. See recollindex(1) for
	    possible values. You can add a stem expansion database for
	    a different language by using <command>recollindex
	    -s</command>, but it will be deleted during the next
	    indexation. Only languages listed in the configuration
	    file are permanent.</para>
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>iconsdir</literal></term>
	    <listitem><para>The name of the directory where
	    <command>recoll</command> result list icons are
	    stored. You can change this if you want different
	    images.</para>
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>dbdir</literal></term>
	    <listitem><para>The name of the Xapian database
	    directory. It will be created if needed when the database
	    is initialized. </para>
	    </listitem>
	  </varlistentry>
	  
	  <varlistentry><term><literal>defaultcharset</literal></term>
	    <listitem><para>The name of the character set used for
	    files that do not contain a character set definition (ie:
	    plain text files). This can be redefined for any
	    subdirectory.</para> 

	  <varlistentry><term><literal>guesscharset</literal></term>
	    <listitem><para>Decide if we try to guess the character
	    set of files if no internal value is available (ie: for
	    plain text files). This does not work well in general, and
	    should probably not be used. </para>
	    </listitem>
	  </varlistentry>

	  <varlistentry><term><literal>usesystemfilecommand</literal></term>
	    <listitem><para>Decide if we use the <command>file -i</command>
            system command as a final step for determining the mime
            type for a file (the main procedure uses suffix
            associations as defined in the  <filename>mimemap</filename>
            file). This can be useful for files with suffixless names,
            but it will also cause the indexation of many bogus "text"
            files.</para> 
	    </listitem>
	  </varlistentry>

	</variablelist>

      </sect2>

      <sect2 id="rclinstall.config.mimemap">
	<title>The mimemap file</title>

	<para><filename>~/.recoll/mimemap</filename> specifies the
	file name extension to mime type mappings.</para> <para>For
	file names without an extension, or with an unknown one, the
	system's <command>file -i</command> command will be executed
	to determine the mime type (this can be switched off inside
	the main configuration file).</para>

	<para><filename>mimemap</filename> also has a list of
	extensions which should be ignored totally (to avoid losing
	time by executing <command>file</command> 
	for things that certainly should not be indexed).</para>

	<para>The mappings can be specified on a per-subtree basis,
	which may be useful in some cases. Example:
	<application>gaim</application> logs have a
	<filename>.txt</filename> extension but 
	should be handled specially, which is possible because they
	are usually all located in one place.</para>

	<para><filename>mimemap</filename> also has a
	<literal>recoll_noindex</literal> variable which is a list of
	suffixes. Matching files will be skipped (avoids unnecessary
	decompressions or <command>file</command> executions). This is
	partially redundant with <literal>skippedNames</literal> in
	the main configuration file, with two differences: it will not
	affect directories, and it can be changed for any
	subdirectory.</para>

      </sect2>

      <sect2 id="rclinstall.config.mimeconf">
	<title>The mimeconf file</title>

	<para><filename>~/.recoll/mimeconf</filename> specifies how the
         different mime types are handled for indexation, and for
         display.</para>

	<para>Changing the indexation parameters is probably not a
         good idea except if you are a &RCL; developper.</para>

	<para>You may want to adjust the external viewers defined in
	 (ie: html is either
	 previewed internally or displayed using 
	 <application>firefox</application>, but you may prefer 
	 <application>mozilla</application>...). Look for the
	 <literal>[view]</literal> section.</para>

	<para>You can also change the icons which are displayed by
         <command>recoll</command> in the result lists (the values are
         the basenames of the png images inside the
         <filename>iconsdir</filename> directory (specified in
         <filename>recoll.conf</filename>).</para> 

      </sect2>

    </sect1>
  </chapter>

</book>