10139N/A<!DOCTYPE REFENTRY PUBLIC "-//Sun Microsystems//DTD DocBook V3.0-Based SolBook Subset V2.0//EN" [

10139N/A<!--ArborText, Inc., 1988-1999, v.4002-->

10139N/A<!ENTITY cmd "gnome-vfs-mime-magic">

10139N/A<!ENTITY % commonents SYSTEM "smancommon.ent">

10139N/A%commonents;

10139N/A<!ENTITY % booktitles SYSTEM "booktitles.ent">

10139N/A%booktitles;

13061N/A<!ENTITY suncopy "Copyright (c) 2003,2008 Sun Microsystems, Inc. All Rights Reserved.">

10139N/A]>

10139N/A<?Pub UDT _bookmark _target>

10139N/A<?Pub EntList brvbar bull cross dash diam diams frac12 frac13 frac14 hellip

10139N/A laquo lArr loz mdash nabla ndash para pound rArr raquo sect yen bsol>

10139N/A<?Pub Inc>

10139N/A<refentry id="gnome-vfs-mime-magic-4">

10139N/A<refmeta><refentrytitle>gnome-vfs-mime-magic.4</refentrytitle><manvolnum>4</manvolnum>

13061N/A<refmiscinfo class="date">14 May 2008</refmiscinfo>

10139N/A<refmiscinfo class="sectdesc">&man4;</refmiscinfo>

10139N/A<refmiscinfo class="software">&release;</refmiscinfo>

10139N/A<refmiscinfo class="arch">generic</refmiscinfo>

10139N/A<refmiscinfo class="copyright">&suncopy;</refmiscinfo>

10139N/A</refmeta>

10139N/A<indexterm><primary>gnome-vfs-mime-magic</primary></indexterm><indexterm>

10139N/A<primary>gnome-mime-info</primary></indexterm><indexterm><primary>gnome-mime-keys

10139N/A</primary></indexterm><indexterm><primary>GNOME VFS MIME detection</primary>

10139N/A</indexterm><refnamediv id="gnome-vfs-mime-magic-4-name"><refname>gnome-vfs-mime-magic</refname>

10139N/A<refname>gnome-vfs.mime</refname><refname>gnome-vfs.keys</refname><refpurpose>

10139N/AGNOME VFS MIME detection</refpurpose></refnamediv>

10139N/A<refsect1 id="gnome-vfs-mime-magic-4-desc"><title>&desc-tt;</title>

13061N/A<para>

13061N/AGnomeVFS is obsolete. Refer to the GNOME Desktop System Administration

13061N/AGuide for information about how to register MIME type information with

13061N/Athe GNOME desktop. The GNOME Desktop System Administration Guide can

13061N/Abe viewed with

13061N/A<citerefentry><refentrytitle>yelp</refentrytitle><manvolnum>1</manvolnum></citerefentry>.

13061N/A</para>

10139N/A<para>On any modern desktop system, each document type or file type must be

10139N/Agiven a unique identification name and icon. In GNOME, this information is

10139N/Aused extensively by the file manager, <citerefentry><refentrytitle>nautilus

10139N/A</refentrytitle><manvolnum>1</manvolnum></citerefentry>. The primary underlying

10139N/Amechanism for providing such definitions is achieved via <command>&cmd;</command>. <command>&cmd;</command>

10139N/Acontains the default file content sniffers for identifying MIME types. The

10139N/Aconcept of MIME magic is similar to that of Solaris <citerefentry><refentrytitle>

10139N/Amagic</refentrytitle><manvolnum>4</manvolnum></citerefentry>.</para>

10139N/A</refsect1>

10139N/A<refsect1 id="gnome-vfs-mime-magic-4-exde"><title>&exde-tt;</title>

10139N/A<refsect2 id="gnome-vfs-mime-magic-4-exde-cmd"><title>&cmd;</title>

10139N/A<para>Each line in the <filename>/etc/gnome/gnome-vfs-mime-magic</filename>

10139N/Afile describes a MIME type. The format of each line is as follows:<screen><computeroutput><replaceable>

10139N/Aoffset_start</replaceable>[:<replaceable>offset_end</replaceable>] <replaceable>

10139N/Apattern_type</replaceable> <replaceable>pattern</replaceable> [&amp;<replaceable>

10139N/Apattern_mask</replaceable>] <replaceable>mime-type</replaceable></computeroutput></screen></para>

10139N/A<para>Each line contains the following fields:</para>

10139N/A<variablelist><varlistentry><term><replaceable>offset_start</replaceable></term>

10139N/A<listitem><para>Decimal number that, with <replaceable>offset_end</replaceable>,

10139N/Aspecifies the bytes offset within the file.</para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><replaceable>offset_end</replaceable></term><listitem>

10139N/A<para>Decimal number that, with <replaceable>offset_start</replaceable>, specifies

10139N/Athe bytes offset within the file.</para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><replaceable>pattern_type</replaceable></term><listitem>

10139N/A<para>Can be one of the following types:</para>

10139N/A<para><literal>byte | short | long | string | date | beshort | belong | bedate

10139N/A| leshort | lelong | ledate</literal></para>

10139N/A<para>where <literal>be</literal> stands for Big Endian and <literal>le</literal>

10139N/Astands for Little Endian.</para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><replaceable>pattern</replaceable></term><listitem><para>

10139N/AAn ASCII string with non-printable characters escaped as hex or octal escape

10139N/Asequences, and spaces and other important whitespace escaped with a backslash

10139N/A(<literal>\\</literal>).</para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><replaceable>pattern_mask</replaceable></term><listitem>

10139N/A<para>A string of hex digits. The mask must be the same specification as the

11925N/Anon-ambiguous patterns.</para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><replaceable>mime-type</replaceable></term><listitem>

10139N/A<para>A valid MIME type.</para>

10139N/A</listitem></varlistentry>

10139N/A</variablelist><para>The magic patterns are matched sequentially from the

11925N/Afirst entry to the last entry of the list. Therefore, you should put the non-ambiguous

10139N/Apatterns at the start of the list. Any pattern that requires a deep seek into

10139N/Athe file should be placed at the end of the list to reduce performance overhead.

10139N/AWhen designing new document formats, include an easily recognizable unique

10139N/Amagic pattern near the start of the file. A good pattern is is at least four

10139N/Abytes long and contains one or two non-printable characters so that text files

10139N/Aare not misidentified.</para>

10139N/A</refsect2>

11904N/A<refsect2 id="gnome-vfs-mime-magic-4-exde-mike"><title>gnome-vfs.mime

10139N/Aand gnome-vfs.keys</title>

10139N/A<para>Apart from file sniffing, GNOME also provide a secondary mechanism to

10139N/Adetermine MIME types. If a file has been sniffed and its type does not match

10139N/Aany of the magic patterns, GNOME looks for files called <filename>/usr/share/gnome/mime-info/*.mime

10139N/A</filename> and processes these. The format of these files is different to

10139N/Athat of pattern magic. Instead of determining the MIME type by reading the

10139N/Acontent of the file, the MIME type of the file is determined by its extension.

10139N/AThe mime info file has the following format: <screen><computeroutput><replaceable>

10139N/Amime_type</replaceable>

10139N/A ext[,<replaceable>prio</replaceable>]: <replaceable>list of extensions for this mime-type

10139N/A</replaceable>

10139N/A regex[,<replaceable>prio</replaceable>]: <replaceable>regular expression that matches the filename

10139N/A</replaceable></computeroutput></screen></para>

10139N/A<para>More than one <literal>ext:</literal> and <literal>regex:</literal>

10139N/Afield can be present for a given MIME type. You can also associate a priority

10139N/Afor each field. The default priority (<replaceable>prio</replaceable>) is

10139N/A1, a higher numerical value indicates a higher priority. The indentation before <literal>

10139N/Aext:</literal> and <literal>regex:</literal> must be a tab character (<literal>

10139N/A\\t</literal>). </para>

10139N/A<para>The searching sequence implies that the magic pattern file has a higher

10139N/Aprecedence over the mime info files. As the mime info files are read alphabetically,

10139N/Athis also determines matching orders for the file extension. </para>

10139N/A<para>For example, the file <filename>FirstFile.mime</filename> contains the

10139N/Afollowing definition:<screen><computeroutput>application/foo

10139N/A ext: foo</computeroutput></screen></para>

10139N/A<para>and the file <filename>SecondFile.mime</filename> contains the following

10139N/Adefinition:<screen><computeroutput>application/mini

10139N/A ext: foo</computeroutput></screen></para>

10139N/A<para>The definition in <filename>FirstFile.mime</filename> will be found

10139N/Afirst and used.</para>

10139N/A<para>For each MIME info file there must be an associated keys file in the

10139N/Asame directory. The key file provides human readable text which can be localized

10139N/Ainto various languages. The data in these keys files is used by the GNOME

10139N/Afile manager, <citerefentry><refentrytitle>nautilus</refentrytitle><manvolnum>

10139N/A1</manvolnum></citerefentry>.</para>

10139N/A</refsect2>

10139N/A</refsect1>

10139N/A<refsect1 id="gnome-vfs-mime-magic-4-exam"><title>&exam-tt;</title>

10139N/A<example role="example"><title>Magic pattern definition for PDF file</title>

10139N/A<para>The following entry in the <filename>/etc/gnome/gnome-vfs-mime-magic

10139N/A</filename> file describes the MIME type of <literal>application/pdf</literal>:<screen><computeroutput>

10139N/A 0 string %PDF- application/pdf </computeroutput> </screen></para>

10139N/A<para>The first 5 characters of a PDF file are <literal>%PDF-</literal>. The

10139N/Asymbols % and - differentiate the PDF file from a text file.</para>

10139N/A</example>

10139N/A<example role="example"><title>Magic pattern definition for BMP file</title>

10139N/A<para>The following entry in the <filename>/etc/gnome/gnome-vfs-mime-magic

10139N/A</filename> file describes the MIME type of <literal>application/bmp</literal>:<screen><computeroutput>

10139N/A0 string BMxxxx\000\000 &amp;0xffff00000000ffff image/bmp</computeroutput>

10139N/A</screen></para>

10139N/A<para>The interpretation of this line is as follows: <itemizedlist>

10139N/A<listitem><para>The first two characters are <literal>BM</literal> and the

10139N/Aseventh and eighth characters are NULL.</para></listitem>

10139N/A<listitem><para>The mask <literal>0xffff00000000ffff</literal> allows the

10139N/Aselction of the first, second, seventh, and eighth characters to be selected

10139N/Afor comparison.</para></listitem>

10139N/A</itemizedlist></para>

10139N/A</example>

10139N/A<example role="example"><title>MIME info file definition for application/x-compress

10139N/A</title>

10139N/A<para>The following entry in the <filename>/etc/gnome/gnome-vfs-mime-magic

10139N/A</filename> file describes the MIME type of <literal>application/x-compress

10139N/A</literal>:<screen><computeroutput>application/x-compress

10139N/A ext: Z</computeroutput> </screen></para>

10139N/A<para>This line indicates that the <literal>x-compress</literal> application

10139N/Asearches for files with a <literal>.Z</literal> extension.</para>

10139N/A<para>The associated keys file entry in the <filename>/usr/share/gnome/mime-info/gnome-vfs.mime

10139N/A</filename> file is as follows (excluding all localized text): <screen><computeroutput>

10139N/Aapplication/x-compress

10139N/A description=compress-compressed file

10139N/A icon_filename=gnome-compressed

10139N/A default_action_type=application

10139N/A category=Packages

10139N/A use_category_default=yes</computeroutput></screen></para>

10139N/A</example>

10139N/A<example role="example"><title>MIME info file definition for application/x-compressed-tar

10139N/A</title>

10139N/A<para>The following entry in the <filename>/etc/gnome/gnome-vfs-mime-magic

10139N/A</filename> file describes the MIME type of <literal>application/x-compressed-tar

10139N/A</literal>:<screen><computeroutput>application/x-compressed-tar

10139N/A regex,2: tar\.gz$

10139N/A ext: tgz</computeroutput> </screen></para>

10139N/A<para>This example uses the priority flag to give <literal>regex</literal>

10139N/Aa higher priority than <literal>ext</literal>, which means that a file with

10139N/Aan extension of <literal>tar.gz</literal> should be matched first (to have

10139N/Aa MIME type of <literal>application/x-compressed-tar)</literal> before <literal>

10139N/Atgz</literal>.</para>

10139N/A</example>

10139N/A</refsect1>

10139N/A<refsect1 id="gnome-vfs-mime-magic-4-file"><title>&file-tt;</title>

10139N/A<para>The following files are used by this application:</para>

10139N/A<variablelist termlength="medium"><varlistentry><term><filename>/etc/gnome/&cmd;</filename>

10139N/A</term><listitem><para></para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><filename>/usr/share/gnome/mime-info/gnome-vfs.mime</filename>

10139N/A</term><listitem><para></para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><filename>/usr/share/gnome/mime-info/gnome-vfs.keys</filename>

10139N/A</term><listitem><para></para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><filename>/usr/share/gnome/mime-info/solaris-gnome2.0.mime

10139N/A</filename> </term><listitem><para></para>

10139N/A</listitem></varlistentry>

10139N/A<varlistentry><term><filename>/usr/share/gnome/mime-info/solaris-gnome2.0.keys

10139N/A</filename> </term><listitem><para></para>

10139N/A</listitem></varlistentry>

10139N/A</variablelist></refsect1>

10139N/A<refsect1 id="gnome-vfs-mime-magic-4-attr"><title>&attr-tt;</title>

10139N/A<para>See <olink targetdocent="REFMAN5" localinfo="attributes-5"><citerefentry>

10139N/A<refentrytitle>attributes</refentrytitle><manvolnum>5</manvolnum></citerefentry></olink>

10139N/Afor descriptions of the following attributes:</para>

10139N/A<informaltable frame="all">

10139N/A<tgroup cols="2" colsep="1" rowsep="1"><colspec colname="COLSPEC0" colwidth="1*">

10139N/A<colspec colname="COLSPEC1" colwidth="1*">

10139N/A<thead>

10139N/A<row><entry align="center" valign="middle">ATTRIBUTE TYPE</entry><entry align="center"

10139N/Avalign="middle">ATTRIBUTE VALUE</entry></row>

10139N/A</thead>

10139N/A<tbody>

18745N/A<row><entry><para>Availability</para></entry><entry><para>library/gnome/gnome-vfs</para></entry>

10139N/A</row>

10139N/A<row><entry colname="COLSPEC0"><para>Interface stability</para></entry><entry

13061N/Acolname="COLSPEC1"><para>Obsolete Volatile</para></entry></row>

10139N/A</tbody>

10139N/A</tgroup>

10139N/A</informaltable>

10139N/A</refsect1>

10139N/A<refsect1 id="gnome-vfs-mime-magic-4-also"><title>&also-tt;</title>

11925N/A<para>

11925N/A<citerefentry><refentrytitle>nautilus</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

11925N/A<citerefentry><refentrytitle>gnome-vfs.applications</refentrytitle><manvolnum>4</manvolnum></citerefentry>,

11925N/A<citerefentry><refentrytitle>libgnomevfs-2</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

11925N/A<citerefentry><refentrytitle>gnome-interfaces</refentrytitle><manvolnum>5</manvolnum></citerefentry>

11925N/A</para>

13061N/A<para>

13061N/ALatest version of the

13061N/A<citetitle>GNOME Desktop System Administration Guide</citetitle>

13061N/Afor your platform.

13061N/A</para>

10139N/A</refsect1>

10139N/A<refsect1 id="gnome-vfs-mime-magic-4-note"><title></title>

11933N/A<para>Written by Ghee Teo, Sun Microsystems Inc., 2003.</para>

10139N/A</refsect1>

10139N/A</refentry>