usermanual.sgml
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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 1.25 2006-11-20 17:46:11 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.binary">installation</link> and start the
<command>recoll</command> user interface, which will index your
home directory by default, allowing you to search immediately after
indexing completes.</para>
<para>Do not do this if your home directory contains 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 may need to install the
appropriate <link linkend="rcl.install.external">
supporting applications</link> for document types that need
them (for example <application>antiword</application> for
ms-word files).</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, in a similar way to Internet search
engines.</para>
<para>&RCL; tries to determine which documents are most relevant to
the search terms you provide. Computer algorithms for determining
relevance can be very complex, and in general are inferior to the
power of the human mind to rapidly determine relevance. The quality
of relevance guessing by the search tool 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>
(example: floor, floors, floored, flooring...). &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 accommodate for misspellings or
phonetic searches. &RCL; currently does not support these
features.</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 (indexing) 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
indexing. </para>
<para>The resulting index 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. (Actually, there is a
way to reconstruct a document from the information in the
index, but the result is not nice, as all formatting,
punctuation and capitalization are lost).</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
index. 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 re-indexing. Storing documents in different
languages in the same index is possible, and useful in
practice, but does introduce possibilities of confusion. &RCL;
currently 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
default configuration is copied into a standard location
(usually something like
<filename>/usr/[local/]share/recoll/examples</filename>)
during installation. The default parameters from this file may
be overridden by values that you set inside your personal
configuration, found by default in the
<filename>.recoll</filename> sub-directory of your home
directory. The default 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.periodic.exec">Indexing</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>Indexing</title>
<sect1 id="rcl.indexing.introduction">
<title>Introduction</title>
<para>Indexing is the process by which the set of documents is
analyzed and the data entered into the database. &RCL; indexing
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 indexing command
(<command>recollindex -z</command>).</para>
<para>&RCL; indexing can be performed with two different
methods:</para>
<itemizedlist>
<listitem>
<formalpara><title>Periodic indexing:</title>
<para>indexing takes place at discrete
times, by executing the <command>recollindex</command>
command. The typical usage is to have a nightly indexing run
<link linkend="rcl.indexing.periodic.automat">programmed</link> into your
<command>cron</command> file.</para>
</formalpara>
</listitem>
<listitem>
<formalpara><title>Real time indexing:</title>
<para>indexing takes place as soon as a file is created or
changed. <command>recollindex</command> runs as a daemon
and uses a file system alteration monitor such as
<application>Fam</application>,
<application>Gamin</application> or
<application>inotify</application> do detect file changes.
Monitoring a big directory tree can consume significant
system resources.</para>
</formalpara>
</listitem>
</itemizedlist>
<para>The choice between the two methods is mostly a matter of
preference, and they can be combined by setting up multiple
indexes (ie: use periodic indexing on a big documentation
directory, and real time indexing on a small home
directory). Monitoring a big file system tree can consume
significant system resources, for dubious gains. <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; indexing 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.external">
installation</link> section.</para>
<para>Without further configuration, &RCL; will index all
appropriate files from your home directory, with a reasonable
set of defaults.</para>
<para>In some cases, it may be interesting to index different
areas of the file system to separate databases. You can do this
by using multiple configuration directories, each indexing a
file system area to a specific database. See the <link
linkend="rcl.search.multidb">section about using multiple
databases</link> for more information on multiple configurations
and indexes. </para>
</sect1>
<sect1 id="rcl.indexing.storage">
<title>Index storage</title>
<para>The default location for the index data is the
<filename>xapiandb</filename> subdirectory of the &RCL;
configuration directory, typically
<filename>$HOME/.recoll/xapiandb/</filename>. This can be
changed via two different methods (with different purposes):</para>
<itemizedlist>
<listitem><para>You can specify a different configuration
directory by setting the <literal>RECOLL_CONFDIR</literal>
environment variable, or using the <literal>-c</literal>
option to the &RCL; commands. This method would typically be
used to index different areas of the file system to
different indexes. For example, if you were to issue the
following commands:
<programlisting>
export RECOLL_CONFDIR=~/.indexes-email
recoll
</programlisting> Then &RCL; would use configuration files
stored in <filename>~/.indexes-email/</filename> and,
(unless specified otherwise in
<filename>recoll.conf</filename>) would look for
the index in <filename>~/.indexes-email/xapiandb/</filename>.
<para>Using multiple configuration directories and
<link linkend="rcl.install.config.recollconf">configuration
options</link> allows you to tailor multiple configurations
and indexes to handle whatever subset of the available data
that you wish to make searchable.</para>
</listitem>
<listitem><para>You can also specify a different storage
location for the index by setting the <literal>dbdir</literal>
parameter in the configuration file
(see the <link linkend="rcl.install.config.recollconf">configuration
section</link>). This method would mainly be of use if you
wanted to keep the configuration directory in its default location,
but desired another location for the index, typically out of
disk occupation concerns.</para>
</listitem>
</itemizedlist>
<para>The size of the index is determined by the size of the set
of documents, but the ratio can vary a lot. For a typical mixed
set of documents, the index size will often be close to
the data set size. In specific cases (a set of compressed
mbox files for example), the index can become much bigger than
the documents. It may also be much smaller if the documents
contain a lot of images or other non-indexed data (an extreme
example being a set of mp3 files where only the tags would be
indexed).</para>
<para>Of course, images, sound and video do not increase the
index size, which means that it will be quite typical nowadays
(2006), that even a big index will be negligible against the
total amount of data on the computer.</para>
<para>The index data directory (<filename>xapiandb</filename>)
only contains data that can be completely rebuilt by an index
run, and it can always be destroyed safely.</para>
<sect2 id="rcl.indexing.storage.security">
<title>Security aspects</title>
<para>The &RCL; index does not hold copies of the indexed
documents. But it does hold enough data to allow for an almost
complete reconstruction. If confidential data is indexed,
access to the database directory should be restricted. </para>
<para>As of version 1.4, &RCL; will create the configuration
directory with a mode of 0700 (access by owner only). As the
index data directory is by default a sub-directory of the
configuration directory, this should result in appropriate
protection.</para>
<para>If you use another setup, you should think of the kind
of protection you need for your index, and set the directory
and files access modes appropriately.</para>
</sect2>
</sect1>
<sect1 id="rcl.indexing.config">
<title>The indexing configuration</title>
<para>You can control which areas of the file system are
indexed, and how files are processed, by setting variables inside
the <link linkend="rcl.install.config">&RCL; configuration
files</link>.</para>
<para>You can also use <link linkend="rcl.search.multidb">multiple
indexes</link> defined by separate configurations, typically to
separate personal and shared indexes, or to take advantage of
the organization of your data to improve search precision.</para>
<para>The first time you start <command>recoll</command>, you
will be asked whether or not you would like recoll to build the
index. If you want to adjust the configuration before indexing,
just click <guilabel>Cancel</guilabel> at this point. That way,
recoll will have created a ~/.recoll directory containing empty
configuration files.</para>
<para>The configuration is documented inside the <link
linkend="rcl.install.config">installation chapter</link> of
this document, or in the recoll.conf(5) man page. The most
immediately useful variable you may interested in is probably <link
linkend="rcl.install.config.recollconf.topdirs">topdirs</link>,
which determines what subtrees get indexed.</para>
<para>The applications needed to index file types other than
text, HTML or email (ie: pdf, postscript, ms-word...) are
described in the <link linkend="rcl.install.external">external
packages section</link></para>
</sect1>
<sect1 id="rcl.indexing.periodic">
<title>Periodic indexing</title>
<sect2 id="rcl.indexing.periodic.exec">
<title>Starting indexing</title>
<para>Indexing is performed either by the
<command>recollindex</command> program, or by the
indexing thread inside the <command>recoll</command>
program (use the <guimenu>File</guimenu> menu). Both programs
will use of the <literal>RECOLL_CONFDIR</literal>
variable or accept a <literal>-c</literal>
<replaceable>confdir</replaceable> option to specify the
configuration directory to be used.</para>
<para>If the <command>recoll</command> program finds no index
when it starts, it will automatically start indexing (except
if canceled).</para>
<para>It is best to avoid interrupting the indexing process, as
this may sometimes leave the index in a bad state. This is
not a serious problem, as you then just need to delete
the index files and restart the indexing. The index 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</command> with option
<literal>-z</literal>, which will reset the database before
indexing.</para>
</sect2>
<sect2 id="rcl.indexing.periodic.automat">
<title>Using <command>cron</command> to automate
indexing</title>
<para>The most common way to set up indexing 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>
</sect2>
</sect1>
<sect1 id="rcl.indexing.monitor">
<title>Real time indexing</title>
<para>Real time monitoring/indexing is performed by starting the
<command>recollindex -m</command> command. With this option,
<command>recollindex</command> will detach from the terminal and
become a daemon, forever monitoring file changes and updating
the index.</para>
<para>The package must have been
<link linkend="rcl.install.building.build">configured</link>
with option <literal>--with-fam</literal> or
<literal>--with-inotify</literal> for the monitoring
code and option to be enabled in
<command>recollindex</command>. This is not currently the
default.</para>
<para>The <filename>rclmon.sh</filename> script can be used to
easily start and stop the daemon. It can be found in the
<filename>examples</filename> directory (typically
<filename>/usr/local/[share/]recoll/examples</filename>).</para>
<para>Starting and stopping the daemon could be performed, for
example, as part of the user session script. For example, my
out of fashion xdm-based session has an .xsession script with
the following lines at the end:</para>
<programlisting>recollconf=$HOME/.recoll-home
recolldata=/usr/local/share/recoll
RECOLL_CONFDIR=$recollconf $recolldata/examples/rclmon.sh start
fvwm
RECOLL_CONFDIR=$recollconf $recolldata/examples/rclmon.sh stop
</programlisting>
<para>The indexing daemon gets started, then the window manager,
for which the session waits. When the window manager exits, the
indexing daemon is stopped, then the session ends (at script
exit). This should be adjusted for your flavour of session
management, and of course, there are other possibilities.</para>
<para>By default, the indexing daemon will write its messages to
a file inside the configuration directory (this is controlled by
the <literal>daemlogfilename</literal> and
<literal>daemloglevel</literal> configuration parameters). You
may want to change this. Also the log file will only be truncated
when the daemon starts. If the daemon runs permanently, the log
file may grow quite big, depending on the log level.</para>
<para>The real time indexing code is relatively young, and there
are still a few quirks. File deletions occurring while the
monitor is not running will not be detected. You'll have to run
a normal incremental indexing pass from time to time to purge
the database. There may still be other problems.</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>
<procedure>
<step><para>Start the <command>recoll</command> program.</para>
</step>
<step><para>Possibly choose a search mode: <guilabel>Any
term</guilabel> or <guilabel>All terms</guilabel> or
<guilabel>File name</guilabel>.</para>
</step>
<step><para>Enter search term(s) in the text field at the top of the
window.</para>
</step>
<step><para>Click the <guilabel>Search</guilabel> button or
hit the <keycap>Enter</keycap> key to start the search.</para>
</step>
</procedure>
<para>The initial default search mode is <guilabel>Any
term</guilabel>. This will look for documents with any of the
search terms (the ones with more terms will get better scores).
<guilabel>All terms</guilabel> will ensure
that only documents with all the terms will be
returned. <guilabel>File name</guilabel> will specifically
look for file names, and allows using wildcards
(<literal>*</literal>, <literal>?</literal> ,
<literal>[]</literal>). </para>
<para>You can search for exact phrases (adjacent words in a
given order) by enclosing the input inside double quotes. Ex:
<literal>"virtual reality"</literal>.</para>
<para>Character case has no influence on search, except that you
can disable stem expansion for any term by capitalizing it. Ie:
a search for <literal>floor</literal> will also normally look for
<literal>flooring</literal>, <literal>floored</literal>, etc., but
a search for <literal>Floor</literal> will only look for
<literal>floor</literal>, in any character case (stemming can
also be disabled globally in the preferences). </para>
<para>&RCL; remembers the last few searches that you
performed. You can use the simple search text entry widget (a
combobox) to recall them (click on the thing at the right of the
text field). Please note, however, that only the search texts
are remembered, not the mode (all/any/file name).</para>
<para>Typing <keycap>Esc</keycap> <keycap>Space</keycap>) while
entering a word in the simple search entry will open a window
with possible completions for the word. The completions are
extracted from the database.</para>
<para>Double-clicking on a word in the result list or a preview
window will insert it into the simple search entry field.</para>
<para>You can use the <guilabel>Tools</guilabel> / <guilabel>Advanced
search</guilabel> dialog for more complex searches.</para>
</sect1>
<sect1 id="rcl.search.reslist">
<title>The result list</title>
<para>After starting a search, a list of results will instantly
be displayed in the main list window.</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>
<para>Clicking on the
<literal>Preview</literal> link for an entry will open an
internal preview window for the document. Further
<literal>Preview</literal> clicks for the same search will open
tabs in the existing preview window. You can use
<keycap>Shift</keycap>+Click to force the creation of another
preview window, which may be useful to view the documents side
by side.</para>
<para>Clicking the <literal>Edit</literal> link will attempt to
start an external viewer (have a look at the
<filename>mimeconf</filename> configuration file to see how
these are configured).</para>
<para>The <literal>Preview</literal> and <literal>Edit</literal>
edit links may not be present for all entries, meaning that
&RCL; has no configured way to preview a given file type (which
was indexed by name only), or no configured external viewer for
the file type. This can sometimes be adjusted simply by tweaking
the <link linkend="rclinstall.config.mimemap">
<filename>mimemap</filename></link> and
<link linkend="rclinstall.config.mimeconf">
<filename>mimeconf</filename></link> configuration files.</para>
<para>You can click on the <literal>Query details</literal> link
at the top of the results page to see the query actually
performed, after stem expansion and other processing.</para>
<para>Double-clicking on any word inside the result list or a
preview window will insert it into the simple search text.</para>
<para>The result list is divided into pages (the size of which
you can change in the preferences). Use the arrow buttons in the
toolbar or the links at the bottom of the page to browse the
results.</para>
<sect2 id="rcl.search.resultlist.menu">
<title>The result list right-click menu</title>
<para>Apart from the preview and edit links, you can display a
pop-up menu by right-clicking over a paragraph in the result
list. This menu has the following entries:</para>
<itemizedlist>
<listitem><para><guilabel>Preview</guilabel></para></listitem>
<listitem><para><guilabel>Edit</guilabel></para></listitem>
<listitem><para><guilabel>Copy File Name</guilabel></para></listitem>
<listitem><para><guilabel>Copy Url</guilabel></para></listitem>
<listitem><para><guilabel>Find similar</guilabel></para></listitem>
</itemizedlist>
<para>The <guilabel>Preview</guilabel> and
<guilabel>Edit</guilabel> entries do the same thing as the
corresponding links. The two following entries will copy either
an URL or the file path to the clipboard, for pasting into
another application.</para>
<para>The <guilabel>Find similar</guilabel> entry will select
a number of relevant term from the current document and enter
them into the simple search field. You can then start a simple
search, with a good chance of finding documents related to the
current result.</para>
</sect2>
</sect1>
<sect1 id="rcl.search.preview">
<title>The preview window</title>
<para>The preview window opens when you first click a
<literal>Preview</literal> link inside the result list.</para>
<para>Subsequent preview requests for a given search open new
tabs in the existing window.</para>
<para>Starting another search and requesting a preview will
create a new preview window. The old one stays open until you
close it.</para>
<para>You can close a preview tab by typing <keycap>^W</keycap>
(<keycap>Ctrl</keycap> + <keycap>W</keycap>) in the
window. Closing the last tab for a window will also close the
window.</para>
<para>Of course you can also close a preview window by using the
window manager button in the top of the frame.</para>
<para>You can display successive or previous documents from the
result list inside a preview tab by typing
<keycap>Shift</keycap>+<keycap>Down</keycap> or
<keycap>Shift</keycap>+<keycap>Up</keycap> (<keycap>Down</keycap>
and <keycap>Up</keycap> are the arrow keys).</para>
<para>The preview tabs have an internal incremental search
function. You initiate the search either by typing a
<keycap>/</keycap> (slash) inside the text area or by clicking
into the <guilabel>Search for:</guilabel> text field and
entering the search string. You can then use the
<guilabel>Next</guilabel> and <guilabel>Previous</guilabel>
buttons to find the next/previous occurrence. You can also type
<keycap>F3</keycap> inside the text area to get to the next
occurrence.</para>
<para>If you have a search string entered and you use ^Up/^Down
to browse the results, the search is initiated for each successive
document. If the string is found, the cursor will be positioned
at the first occurrence of the search string.</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. It has a number of entry fields, each of which
is configurable for the following modes:
<itemizedlist>
<listitem><para>All terms.</para>
</listitem>
<listitem><para>Any term.</para>
</listitem>
<listitem><para>None of the terms.</para>
</listitem>
<listitem><para>Phrase (exact terms in order within an
adjustable window).</para>
</listitem>
<listitem><para>Proximity (terms in any order within an
adjustable window).</para>
</listitem>
<listitem><para>Filename search with wildcards.</para>
</listitem>
</itemizedlist>
</para>
<para>Additional entry fields can be created by clicking the
<guilabel>Add clause</guilabel> button.</para>
<para>All relevant fields will be combined by an implicit AND
or OR conjunction. All types of clauses except "phrase" and
"near" can accept a mix of single words and phrases enclosed
in double quotes. Stemming expansion will be performed for all
terms not beginning with a capital letter, except for "phrase"
clauses.</para>
<para>Advanced search will also 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...). The state of the
file type selection can be saved as the default (the file type
filter will not be activated at program start-up, but the lists
will be in the restored state).</para>
<para>You can also restrict the search results
to a sub-tree of the indexed area. If you need to do this often,
you may think of setting up multiple indexes instead, as the
performance will be much better.</para>
<para>Click on the <guilabel>Start Search</guilabel> button in
the advanced search dialog, or type <keycap>Enter</keycap> in
any text field to start the search. The button in
the main window always performs a simple search.</para>
<para>Click on the <literal>Show query details</literal> link at
the top of the result page to see the query expansion.</para>
</sect1>
<sect1 id="rcl.search.termexplorer">
<title>The term explorer tool</title>
<para>&RCL; automatically manages the expansion of search terms
to their derivatives (ie: plural/singular, verb
inflections). But there are other cases where the exact search
term is not known. For example, you may not remember the exact
spelling, or only know the beginning of the name.</para>
<para>The term explorer tool (started from the toolbar icon or
from the <guilabel>Term explorer</guilabel> entry of the
<guilabel>Tools</guilabel> menu) can be used to search the full index
terms list. It has three modes of operations:</para>
<variablelist>
<varlistentry>
<term>Wildcard</term>
<listitem><para>In this mode of operation, you can enter a
search string with shell-like wildcards (*, ?). ie:
<replaceable>xapi*</replaceable> .</para></listitem>
</varlistentry>
<varlistentry>
<term>Regular expression</term>
<listitem><para>This mode will accept a regular expression
as input. Example:
<replaceable>word[0-9]+</replaceable> . The regular
expression is anchored by enclosing in
<literal>^</literal> and <literal>$</literal> before
execution.</para></listitem>
</varlistentry>
<varlistentry>
<term>Spelling/Phonetic</term> <listitem><para>In this
mode, you enter the term as you think it is spelled, and
&RCL; will do its best to find index terms that sound like
your entry. This mode uses the
<application>Aspell</application> spelling application,
which must be installed on your system for things to
work. The language which is used to build the dictionary
out of the index terms (which is done at the end of an
indexing pass) is the one defined by your NLS
environment. Weird things will probably happen if
languages are mixed up.</para></listitem>
</varlistentry>
</variablelist>
<para>Note that in cases where &RCL; does not know the beginning
of the string to search for (ie a wildcard expression like
<replaceable>*coll</replaceable>), the expansion can take quite
a long time because the full index term list will have to be
processed. The expansion is currently limited at 200 results for
wildcards and regular expressions.</para>
<para>Double-clicking on a term in the result list will insert
it into the simple search entry field. You can also cut/paste
between the result list and any entry field (the end of lines
will be taken care of).</para>
</sect1>
<sect1 id="rcl.search.multidb">
<title>Multiple databases</title>
<para>Multiple &RCL; databases or indexes can be created by
using several configuration directories which are usually set to
index different areas of the file system. A specific index can
be selected for updating or searching, using the
<literal>RECOLL_CONFDIR</literal> environment variable or the
<literal>-c</literal> option to <command>recoll</command> and
<command>recollindex</command>.</para>
<para>A <command>recollindex</command> program instance can only
update one specific index.</para>
<para>A <command>recoll</command> program instance is also
associated with a specific index, which is the one to be
updated by its indexing thread, but it can use any
number of &RCL; indexes for searching. The external indexes
can be selected through the <guilabel>external
indexes</guilabel> tab in the preferences dialog.</para>
<para>Index selection is performed in two phases. A set of all
usable indexes must first be defined, and then the subset of
indexes to be used for searching. Of course, these parameters
are retained across program executions (there are kept
separately for each &RCL; configuration). The set of all indexes
is usually quite stable, while the active ones might typically
be adjusted quite frequently.</para>
<para>The main index (defined by
<literal>RECOLL_CONFDIR</literal>) is always active. If this is
undesirable, you can set up your base configuration to index
an empty directory.</para>
<para>As building the set of all indexes can be a little tedious
when done through the user interface, you can use the
<literal>RECOLL_EXTRA_DBS</literal> environment
variable to provide an initial set. This might typically be
set up by a system administrator so that every user does not
have to do it. The variable should define a colon-separated list
of index directories, ie:
</para>
<screen>export RECOLL_EXTRA_DBS=/some/place/xapiandb:/some/other/db</screen>
<para>A typical usage scenario for the multiple index feature
would be for a system administrator to set up a central index
for shared data, that you may choose to search, or not, in
addition to your personal data. Of course, there are other
possibilities. There are many cases where you know the subset of
files that you want to be searched for a given query, and where
restricting the query will much improve the precision of the
results. This can also be performed with the directory filter in
advanced search, but multiple indexes will have much better
performance and may be worth the trouble.</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>Sorting search results</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 explicitly
reset, or the program exits. An activated sort is indicated in
the result list header.</para>
</sect1>
<sect1 id="rcl.search.tips">
<title>Search tips, shortcuts</title>
<formalpara><title>Term completion</title>
<para>Typing <keycap>Esc</keycap> <keycap>Space</keycap> in
the simple search entry field while entering a word will
either complete the current word if its beginning matches a
unique term in the index, or open a window to propose a list
of completions.</para>
</formalpara>
<formalpara><title>Picking up new terms from result or preview
text</title>
<para>Double-clicking on a word in the result list or in a
preview window will copy it to the simple search entry field.</para>
</formalpara>
<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. You can also disable stem expansion or change the
stemming language in the preferences.</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. Phrases can be entered along
simple terms in all simple or advanced search entry fields
(except <guilabel>This exact phrase</guilabel>).</para>
</formalpara>
<formalpara><title>Browsing the result list inside a preview
window (1.5)</title>
<para>Entering <keycap>Shift-Down</keycap> or <keycap>Shift-Up</keycap>
(<keycap>Shift</keycap> + an arrow key) in a preview window will
display the next or the previous document from the result
list. Any secondary search currently active will be executed on
the new document.</para>
</formalpara>
<formalpara><title>Forced opening of a preview window (1.6)</title>
<para>You can use <keycap>Shift</keycap>+Click on a result list
<literal>Preview</literal> link to force the creation of a
preview window instead of a new tab in the existing one.</para>
</formalpara>
<formalpara><title>AutoPhrases (1.5)</title>
<para>This option can be set in the preferences dialog. If it is
set, a phrase will be automatically built and added to simple
searches when looking for <literal>Any terms</literal>. This
will not change radically the results, but will give a relevance
boost to the results where the search terms appear as a
phrase. Ie: searching for <literal>virtual reality</literal>
will still find all documents where either
<literal>virtual</literal> or <literal>reality</literal> or
both appear, but those which contain <literal>virtual
reality</literal> should appear sooner in the list.</para>
<formalpara><title>Finding related documents</title>
<para>Selecting the <guilabel>Find similar documents</guilabel> entry
in the result list paragraph right-click menu will select a
set of "interesting" terms from the current result, and insert
them into the simple search entry field. You can then possibly
edit the list and start a search to find documents which may
be apparented to the current result.</para>
</formalpara>
<formalpara><title>File names</title>
<para>File names are added as terms during indexing, and you can
specify them as ordinary terms in normal search fields (&RCL; used
to index all directories in the file path as terms. This has been
abandoned as it did not seem really useful). Alternatively, you
can use the specific file name search which will
<emphasis>only</emphasis> look for file names and can use wildcard
expansion.</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>Closing previews</title>
<para>Entering <keycap>^W</keycap> in a tab will
close it (and, for the last tab, close the preview
window). Entering <keycap>Esc</keycap> will close the preview
window and all its tabs.</para>
</formalpara>
<formalpara><title>Quitting</title>
<para>Entering <keycap>^Q</keycap> almost anywhere will
close the application.</para>
</formalpara>
</sect1>
<sect1 id="rcl.search.custom">
<title>Customizing the search interface</title>
<para>It is possible to customize 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, dealing with the
interface itself, and with the parameters used for searching and
returning results.</para>
<formalpara><title>User interface parameters:</title>
<para>
<itemizedlist>
<listitem><para><guilabel>Number of results in a result
page</guilabel></para>
</listitem>
<listitem><para><guilabel>Result list font</guilabel>: There
is quite a lot of information shown in the result list, and
you may want to customize the font and/or font size. The rest
of the fonts used by &RCL; are determined by your generic QT
config (try the <command>qtconfig</command> command.</para>
</listitem>
<listitem><para><guilabel>Result paragraph format
string</guilabel>: allows you to change the presentation of
each result list entry. This is a qt-html string where the
following printf-like <literal>%</literal> substitutions will
be performed:
<itemizedlist>
<listitem>
<formalpara><title>%A</title><para>Abstract</para></formalpara>
</listitem>
<listitem><formalpara><title>%D</title><para>Date</para></formalpara>
</listitem>
<listitem><formalpara><title>%K</title><para>Keywords (if
any)</para></formalpara>
</listitem>
<listitem><formalpara><title>%L</title><para>Preview and
Edit links</para></formalpara>
</listitem>
<listitem><formalpara><title>%M</title><para>Mime
type</para></formalpara>
</listitem>
<listitem><formalpara><title>%N</title><para>result Number
</para></formalpara>
</listitem>
<listitem><formalpara><title>%R</title><para>Relevance
percentage</para></formalpara>
</listitem>
<listitem><formalpara><title>%S</title><para>Size
information</para></formalpara>
</listitem>
<listitem><formalpara><title>%T</title><para>Title</para>
</formalpara>
</listitem>
<listitem><formalpara><title>%U</title><para>Url</para></formalpara>
</listitem>
</itemizedlist>
The default value for the string is:
<programlisting>%R %S %L &nbsp;&nbsp;<b>%T</b><br>
%M&nbsp;%D&nbsp;&nbsp;&nbsp;<i>%U</i><br>
%A %K
</programlisting>
You may, for example, try the following for a more web-like
experience (but the document title will not act as a link):
<programlisting><u><b><font size=+1 color=#1111cf>%T</font></b></u><br>
%A<font color=#008000>%U - %S</font> - %L
</programlisting>
</para>
</listitem>
<listitem><para><guilabel>HTML help browser</guilabel>: this
will let you chose your preferred browser which will be
started from the <guimenu>Help</guimenu> menu to read the user
manual. You can enter a simple name if the command is in your
PATH, or browse for a full pathname.</para>
</listitem>
<listitem><para><guilabel>Show document type icons in result
list</guilabel>: icons in the result list can be turned
off. They take quite a lot of space and convey relatively
little useful information.</para>
</listitem>
<listitem><para><guilabel>Auto-start simple search on
white space entry</guilabel>: if this is checked, a search will
be executed each time you enter a space in the simple search
input field. This lets you look at the result list as you
enter new terms. This is off by default, you may like it or
not...</para>
</listitem>
</itemizedlist>
</para>
</formalpara>
<formalpara><title>Search parameters:</title>
<para>
<itemizedlist>
<listitem><para><guilabel>Stemming language</guilabel>:
stemming obviously depends on the document's language. This
listbox will let you chose among the stemming databases which
were built during indexing (this is set in the <link
linkend="rcl.install.config.recollconf">main configuration
file</link>), or later added with
<command>recollindex -s</command> (See the recollindex
manual). Stemming languages which are dynamically added will be
deleted at the next indexing pass unless they are also added in
the configuration file.</para>
</listitem>
<listitem><para><guilabel>Dynamically build
abstracts</guilabel>: this decides if &RCL; tries to build
document abstracts when displaying the result list. Abstracts
are constructed by taking context from the document
information, around the search terms. This can slow down
result list display significantly for big documents, and you
may want to turn it off.</para>
</listitem>
<listitem><para><guilabel>Replace abstracts from
documents</guilabel>: this decides if we should synthesize and
display an abstract in place of an explicit abstract found
within the document itself.</para>
</listitem>
<listitem><para><guilabel>Synthetic abstract size</guilabel>:
adjust to taste...</para>
</listitem>
<listitem><para><guilabel>Synthetic abstract context
words</guilabel>: how many words should be displayed around
each term occurrence.</para>
</listitem>
</itemizedlist>
</para>
</formalpara>
<formalpara id="rcl.search.custom.extradb">
<title>External indexes:</title>
<para>This panel will let you browse for additional indexes
that you may want to search. External indexes are designated by
their database directory (ie:
<filename>/home/someothergui/.recoll/xapiandb</filename>,
<filename>/usr/local/recollglobal/xapiandb</filename>).</para>
<para>Once entered, the indexes will appear in the
<guilabel>All indexes</guilabel> list, and you can
chose which ones you want to use at any moment by transferring
them to/from the <guilabel>Active indexes</guilabel>
list.</para>
<para>Your main database (the one the current configuration
indexes to), is always implicitly active. If this is not
desirable, you can set up your configuration so that it indexes,
for example, an empty directory.</para>
</sect1>
</chapter>
<chapter id="rcl.install">
<title>Installation</title>
<sect1 id="rcl.install.binary">
<title>Installing a prebuilt copy</title>
<para>Recoll binary installations are always linked statically
to the xapian libraries, and have no other dependencies. You
will only have to check or install
<link linkend="rcl.install.external">supporting
applications</link> for the file types that you want to index
beyond text, HTML and mail files.</para>
<sect2 id="rcl.install.binary.package">
<title>Installing through a package system</title>
<para>If you use a BSD-type port system or a
prebuilt package (RPM or other), just follow the usual
procedure, and maybe have a look at the <link
linkend="rcl.install.config">configuration
section</link> (but this may not be necessary for a quick
test with default parameters).</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 (that is, just type
<literal>make install</literal>). The binary trees are built for
installation to <filename>/usr/local</filename>.</para>
<para>You may then need to install external applications to process
some file types that you want indexed (ie: acrobat,
postscript ...). See next section.</para>
<para>Finally, you may want to have a look at the <link
linkend="rcl.indexing.config">configuration section</link>.</para>
</sect2>
</sect1>
<sect1 id="rcl.install.external">
<title>Supporting packages</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 (these are run-time dependencies. None is needed for
building &RCL;):</para>
<itemizedlist>
<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>MS Word: <ulink url="http://www.winfield.demon.nl">
antiword</ulink>.</para>
</listitem>
<listitem><para>MS Excel and PowerPoint:
<ulink url="http://www.45.free.net/~vitus/software/catdoc/">
catdoc</ulink>.</para>
</listitem>
<listitem>
<para>RTF: <ulink
url="http://www.gnu.org/software/unrtf/unrtf.html">unrtf</ulink>
</para>
</listitem>
<listitem>
<para>dvi: <ulink
url="http://www.radicaleye.com/dvips.html">dvips</ulink></para>
</listitem>
<listitem>
<para>djvu:
<ulink
url="http://djvulibre.djvuzone.org/doc/index.html">DjVuLibre
</ulink></para>
</listitem>
<listitem><para>MP3: &RCL; will use the
<command>id3info</command> command from the <ulink
url="http://id3lib.sourceforge.net/">id3lib</ulink> package to
extract tag information. Without it, only the file names will
be indexed.</para>
</listitem>
</itemizedlist>
<para>Text, HTML, mail folders and Openoffice files are
processed internally.</para>
</sect1>
<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; development currently uses version 0.9.5), and the <ulink
url="http://www.trolltech.com/products/qt/index.html">qt
run-time and development packages</ulink> (&RCL; development
currently uses version 3.3.5, but any 3.3 version is
probably OK).</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 &XAP; 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>
<sect2 id="rcl.install.building.build">
<title>Building</title>
<para>&RCL; has been built on
Linux (redhat7.3, mandriva 2005/6, Fedora Core 3/4/5), 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:
if <filename>qt.h</filename> is
<filename>/usr/local/qt/include/qt.h</filename>, QTDIR
should be <filename>/usr/local/qt</filename>).</para>
</listitem>
<listitem><para><literal>QMAKESPECS</literal> should
be set to the name of one of the
<application>qt</application> mkspecs sub-directories (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>
<formalpara><title>Configure
options:</title><para><literal>--without-aspell</literal>
will disable the code for phonetic matching of search
terms. <literal>--with-fam</literal> or
<literal>--with-inotify</literal> will enable the code for
real time indexing. Refer to <literal>configure
--help</literal> output for details.</para>
<para>Normal procedure:</para>
<screen>
<userinput>cd recoll-xxx</userinput>
<userinput>configure</userinput>
<userinput>make</userinput>
<userinput>(practices usual hardship-repelling invocations)</userinput>
</screen>
<para>There little auto-configuration. 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
<replaceable>prefix</replaceable></userinput>, in the root
of the source tree. This will copy the commands to
<filename><replaceable>prefix</replaceable>/bin</filename>
and the sample configuration files, scripts and other shared
data to
<filename><replaceable>prefix</replaceable>/share/recoll</filename>.</para>
<para>If the installation prefix given to
<command>recollinstall</command> is different from what was
specified when executing <command>configure</command>, you
will have to set the <literal>RECOLL_DATADIR</literal>
environment variable to indicate where the shared data is to
be found.</para>
<para>You can then proceed to <link
linkend="rcl.install.config">configuration</link>. </para>
</sect2>
</sect1>
<sect1 id="rcl.install.config">
<title>Configuration overview</title>
<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 default
files, and we will just give a general overview here.</para>
<para>There are two sets of configuration files. The system-wide
files are kept in a directory named like
<filename>/usr/[local/]share/recoll/examples</filename>,
they define default values for the system. A parallel set of
files exists by default in the <filename>.recoll</filename> directory
in your home. This directory can be changed with the
<literal>RECOLL_CONFDIR</literal> environment variable or the -c
option parameter to <command>recoll</command> and
<command>recollindex</command>.</para>
<para>If the <filename>.recoll</filename> directory does not
exist when <command>recoll</command> or
<command>recollindex</command> are started, it
will be created with a set of empty configuration files.
<command>recoll</command> will give you a
chance to edit the configuration file before starting
indexing. <command>recollindex</command> will
proceed immediately.</para>
<para>All configuration files share the same format. For
example, 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 definitions allow redefining some parameters for
a directory sub-tree. They stay in effect until another
section definition, or the end of file, is encountered. Some
of the parameters used for indexing are looked up
hierarchically from the current directory location
upwards. 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.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, start
<command>recoll</command> to create a blank
configuration, click <guimenu>Cancel</guimenu>, and edit
the configuration file before restarting the command. This
will start the initial indexing, which may take some time.</para>
<para>Paramers:</para>
<variablelist>
<varlistentry id="rcl.install.config.recollconf.topdirs">
<term><literal>topdirs</literal></term>
<listitem><para>Specifies the list of directories or files to
index (recursively for directories). The indexer will not
follow symbolic links inside the indexed trees. If an entry in
the <literal>topdirs</literal> list is a symbolic link,
indexing will not start and will generate an error.</para>
</listitem>
</varlistentry>
<varlistentry><term><literal>dbdir</literal></term>
<listitem><para>The name of the Xapian data directory. It
will be created if needed when the index is
initialized. If this is not an absolute path, it will be
interpreted relative to the configuration directory.</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 sub-directories, 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,daemloglevel</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. The
<literal>daem</literal>version is specific to the indexing monitor
daemon.</para>
</listitem>
</varlistentry>
<varlistentry><term><literal>logfilename,
daemlogfilename</literal></term>
<listitem><para>Where the messages should go. 'stderr' can
be used as a special value, and is the default. The
<literal>daem</literal>version is specific to the indexing monitor
daemon.</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 sub-directory. </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
indexing. Only languages listed in the configuration
file are permanent.</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
sub-directory. If it is not set at all, the character set
used is the one defined by the nls environment (LC_ALL,
LC_CTYPE, LANG), or iso8859-1 if nothing is set.</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 suffix-less names,
but it will also cause the indexing of many bogus "text"
files.</para>
</listitem>
</varlistentry>
<varlistentry><term><literal>indexallfilenames</literal></term>
<listitem><para>&RCL; indexes file names in a special
section of the database to allow specific file names
searches using wild cards. This parameter decides if
file name indexing is performed only for files with mime
types that would qualify them for full text indexing, or
for all files inside the selected subtrees, independently of
mime type.</para>
</listitem>
</varlistentry>
<varlistentry><term><literal>idxabsmlen</literal></term>
<listitem><para>&RCL; stores an abstract for each indexed
file inside the database. This is so that they can be
displayed inside the result lists without decoding the
original file. This parameter defines the size of the
stored abstract (which can come from an actual section or
just be the beginning of the text). The default value is 250.
</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>
</variablelist>
</sect2>
<sect2 id="rclinstall.config.mimemap">
<title>The mimemap file</title>
<para><filename>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>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
sub-directory.</para>
</sect2>
<sect2 id="rclinstall.config.mimeconf">
<title>The mimeconf file</title>
<para><filename>mimeconf</filename> specifies how the
different mime types are handled for indexing, and for
display.</para>
<para>Changing the indexing parameters is probably not a
good idea except if you are a &RCL; developers.</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>, your
<application>openoffice.org</application>
program might be named <command>oofice</command> instead of
<command>openoffice</command> ...). 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>