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diff --git a/fontconfig/doc/fontconfig-user.sgml b/fontconfig/doc/fontconfig-user.sgml index 217feb97a..efa01aa58 100644 --- a/fontconfig/doc/fontconfig-user.sgml +++ b/fontconfig/doc/fontconfig-user.sgml @@ -1,704 +1,704 @@ -<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V3.1//EN" [ -<!ENTITY version SYSTEM "version.sgml"> -<!ENTITY confdir SYSTEM "confdir.sgml"> -]> -<!-- - Copyright © 2003 Keith Packard - - Permission to use, copy, modify, distribute, and sell this software and its - documentation for any purpose is hereby granted without fee, provided that - the above copyright notice appear in all copies and that both that - copyright notice and this permission notice appear in supporting - documentation, and that the name of the author(s) not be used in - advertising or publicity pertaining to distribution of the software without - specific, written prior permission. The authors make no - representations about the suitability of this software for any purpose. It - is provided "as is" without express or implied warranty. - - THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, - INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO - EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR - CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, - DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER - TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR - PERFORMANCE OF THIS SOFTWARE. ---> -<refentry> -<refmeta> - <refentrytitle>fonts-conf</refentrytitle> - <manvolnum>5</manvolnum> -</refmeta> -<refnamediv> - <refname>fonts.conf</refname> - <refpurpose>Font configuration files</refpurpose> -</refnamediv> -<refsynopsisdiv> -<synopsis> - &confdir;/fonts.conf - &confdir;/fonts.dtd - &confdir;/conf.d - ~/.fonts.conf.d - ~/.fonts.conf -</synopsis> -</refsynopsisdiv> -<refsect1><title>Description</title> - <para> -Fontconfig is a library designed to provide system-wide font configuration, -customization and application access. - </para> -</refsect1> -<refsect1><title>Functional Overview</title> - <para> -Fontconfig contains two essential modules, the configuration module which -builds an internal configuration from XML files and the matching module -which accepts font patterns and returns the nearest matching font. - </para> - <refsect2><title>Font Configuration</title> - <para> -The configuration module consists of the FcConfig datatype, libexpat and -FcConfigParse which walks over an XML tree and amends a configuration with -data found within. From an external perspective, configuration of the -library consists of generating a valid XML tree and feeding that to -FcConfigParse. The only other mechanism provided to applications for -changing the running configuration is to add fonts and directories to the -list of application-provided font files. - </para><para> -The intent is to make font configurations relatively static, and shared by -as many applications as possible. It is hoped that this will lead to more -stable font selection when passing names from one application to another. -XML was chosen as a configuration file format because it provides a format -which is easy for external agents to edit while retaining the correct -structure and syntax. - </para><para> -Font configuration is separate from font matching; applications needing to -do their own matching can access the available fonts from the library and -perform private matching. The intent is to permit applications to pick and -choose appropriate functionality from the library instead of forcing them to -choose between this library and a private configuration mechanism. The hope -is that this will ensure that configuration of fonts for all applications -can be centralized in one place. Centralizing font configuration will -simplify and regularize font installation and customization. - </para> - </refsect2> - <refsect2> - <title>Font Properties</title> - <para> -While font patterns may contain essentially any properties, there are some -well known properties with associated types. Fontconfig uses some of these -properties for font matching and font completion. Others are provided as a -convenience for the applications' rendering mechanism. - </para> - <programlisting> - Property Type Description - -------------------------------------------------------------- - family String Font family names - familylang String Languages corresponding to each family - style String Font style. Overrides weight and slant - stylelang String Languages corresponding to each style - fullname String Font full names (often includes style) - fullnamelang String Languages corresponding to each fullname - slant Int Italic, oblique or roman - weight Int Light, medium, demibold, bold or black - size Double Point size - width Int Condensed, normal or expanded - aspect Double Stretches glyphs horizontally before hinting - pixelsize Double Pixel size - spacing Int Proportional, dual-width, monospace or charcell - foundry String Font foundry name - antialias Bool Whether glyphs can be antialiased - hinting Bool Whether the rasterizer should use hinting - hintstyle Int Automatic hinting style - verticallayout Bool Use vertical layout - autohint Bool Use autohinter instead of normal hinter - globaladvance Bool Use font global advance data - file String The filename holding the font - index Int The index of the font within the file - ftface FT_Face Use the specified FreeType face object - rasterizer String Which rasterizer is in use - outline Bool Whether the glyphs are outlines - scalable Bool Whether glyphs can be scaled - scale Double Scale factor for point->pixel conversions - dpi Double Target dots per inch - rgba Int unknown, rgb, bgr, vrgb, vbgr, - none - subpixel geometry - lcdfilter Int Type of LCD filter - minspace Bool Eliminate leading from line spacing - charset CharSet Unicode chars encoded by the font - lang String List of RFC-3066-style languages this - font supports - fontversion Int Version number of the font - capability String List of layout capabilities in the font - embolden Bool Rasterizer should synthetically embolden the font - </programlisting> - </refsect2> - <refsect2> - <title>Font Matching</title> - <para> -Fontconfig performs matching by measuring the distance from a provided -pattern to all of the available fonts in the system. The closest matching -font is selected. This ensures that a font will always be returned, but -doesn't ensure that it is anything like the requested pattern. - </para><para> -Font matching starts with an application constructed pattern. The desired -attributes of the resulting font are collected together in a pattern. Each -property of the pattern can contain one or more values; these are listed in -priority order; matches earlier in the list are considered "closer" than -matches later in the list. - </para><para> -The initial pattern is modified by applying the list of editing instructions -specific to patterns found in the configuration; each consists of a match -predicate and a set of editing operations. They are executed in the order -they appeared in the configuration. Each match causes the associated -sequence of editing operations to be applied. - </para><para> -After the pattern has been edited, a sequence of default substitutions are -performed to canonicalize the set of available properties; this avoids the -need for the lower layers to constantly provide default values for various -font properties during rendering. - </para><para> -The canonical font pattern is finally matched against all available fonts. -The distance from the pattern to the font is measured for each of several -properties: foundry, charset, family, lang, spacing, pixelsize, style, -slant, weight, antialias, rasterizer and outline. This list is in priority -order -- results of comparing earlier elements of this list weigh more -heavily than later elements. - </para><para> -There is one special case to this rule; family names are split into two -bindings; strong and weak. Strong family names are given greater precedence -in the match than lang elements while weak family names are given lower -precedence than lang elements. This permits the document language to drive -font selection when any document specified font is unavailable. - </para><para> -The pattern representing that font is augmented to include any properties -found in the pattern but not found in the font itself; this permits the -application to pass rendering instructions or any other data through the -matching system. Finally, the list of editing instructions specific to -fonts found in the configuration are applied to the pattern. This modified -pattern is returned to the application. - </para><para> -The return value contains sufficient information to locate and rasterize the -font, including the file name, pixel size and other rendering data. As -none of the information involved pertains to the FreeType library, -applications are free to use any rasterization engine or even to take -the identified font file and access it directly. - </para><para> -The match/edit sequences in the configuration are performed in two passes -because there are essentially two different operations necessary -- the -first is to modify how fonts are selected; aliasing families and adding -suitable defaults. The second is to modify how the selected fonts are -rasterized. Those must apply to the selected font, not the original pattern -as false matches will often occur. - </para> - </refsect2> - <refsect2><title>Font Names</title> - <para> -Fontconfig provides a textual representation for patterns that the library -can both accept and generate. The representation is in three parts, first a -list of family names, second a list of point sizes and finally a list of -additional properties: - </para> - <programlisting> - <families>-<point sizes>:<name1>=<values1>:<name2>=<values2>... - </programlisting> - <para> -Values in a list are separated with commas. The name needn't include either -families or point sizes; they can be elided. In addition, there are -symbolic constants that simultaneously indicate both a name and a value. -Here are some examples: - </para> - <programlisting> - Name Meaning - ---------------------------------------------------------- - Times-12 12 point Times Roman - Times-12:bold 12 point Times Bold - Courier:italic Courier Italic in the default size - Monospace:matrix=1 .1 0 1 The users preferred monospace font - with artificial obliquing - </programlisting> - <para> -The '\', '-', ':' and ',' characters in family names must be preceded by a -'\' character to avoid having them misinterpreted. Similarly, values -containing '\', '=', '_', ':' and ',' must also have them preceded by a -'\' character. The '\' characters are stripped out of the family name and -values as the font name is read. - </para> - </refsect2> -</refsect1> -<refsect1><title>Debugging Applications</title> - <para> -To help diagnose font and applications problems, fontconfig is built with a -large amount of internal debugging left enabled. It is controlled by means -of the FC_DEBUG environment variable. The value of this variable is -interpreted as a number, and each bit within that value controls different -debugging messages. - </para> - <programlisting> - Name Value Meaning - --------------------------------------------------------- - MATCH 1 Brief information about font matching - MATCHV 2 Extensive font matching information - EDIT 4 Monitor match/test/edit execution - FONTSET 8 Track loading of font information at startup - CACHE 16 Watch cache files being written - CACHEV 32 Extensive cache file writing information - PARSE 64 (no longer in use) - SCAN 128 Watch font files being scanned to build caches - SCANV 256 Verbose font file scanning information - MEMORY 512 Monitor fontconfig memory usage - CONFIG 1024 Monitor which config files are loaded - LANGSET 2048 Dump char sets used to construct lang values - OBJTYPES 4096 Display message when value typechecks fail - </programlisting> - <para> -Add the value of the desired debug levels together and assign that (in -base 10) to the FC_DEBUG environment variable before running the -application. Output from these statements is sent to stdout. - </para> -</refsect1> -<refsect1><title>Lang Tags</title> - <para> -Each font in the database contains a list of languages it supports. This is -computed by comparing the Unicode coverage of the font with the orthography -of each language. Languages are tagged using an RFC-3066 compatible naming -and occur in two parts -- the ISO 639 language tag followed a hyphen and then -by the ISO 3166 country code. The hyphen and country code may be elided. - </para><para> -Fontconfig has orthographies for several languages built into the library. -No provision has been made for adding new ones aside from rebuilding the -library. It currently supports 122 of the 139 languages named in ISO 639-1, -141 of the languages with two-letter codes from ISO 639-2 and another 30 -languages with only three-letter codes. Languages with both two and three -letter codes are provided with only the two letter code. - </para><para> -For languages used in multiple territories with radically different -character sets, fontconfig includes per-territory orthographies. This -includes Azerbaijani, Kurdish, Pashto, Tigrinya and Chinese. - </para> -</refsect1> -<refsect1><title>Configuration File Format</title> - <para> -Configuration files for fontconfig are stored in XML format; this -format makes external configuration tools easier to write and ensures that -they will generate syntactically correct configuration files. As XML -files are plain text, they can also be manipulated by the expert user using -a text editor. - </para><para> -The fontconfig document type definition resides in the external entity -"fonts.dtd"; this is normally stored in the default font configuration -directory (&confdir;). Each configuration file should contain the -following structure: - <programlisting> - <?xml version="1.0"?> - <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> - <fontconfig> - ... - </fontconfig> - </programlisting> - </para> -<refsect2><title><literal><fontconfig></literal></title><para> -This is the top level element for a font configuration and can contain -<literal><dir></literal>, <literal><cache></literal>, <literal><include></literal>, <literal><match></literal> and <literal><alias></literal> elements in any order. - </para></refsect2> - <refsect2><title><literal><dir></literal></title><para> -This element contains a directory name which will be scanned for font files -to include in the set of available fonts. - </para></refsect2> - <refsect2><title><literal><cache></literal></title><para> -This element contains a file name for the per-user cache of font -information. If it starts with '~', it refers to a file in the users -home directory. This file is used to hold information about fonts that -isn't present in the per-directory cache files. It is automatically -maintained by the fontconfig library. The default for this file -is ``~/.fonts.cache-<literal><version></literal>'', where <literal><version></literal> is the font configuration -file version number (currently 2). - </para></refsect2> - <refsect2><title><literal><include ignore_missing="no"></literal></title><para> -This element contains the name of an additional configuration file or -directory. If a directory, every file within that directory starting with an -ASCII digit (U+0030 - U+0039) and ending with the string ``.conf'' will be processed in sorted order. When -the XML datatype is traversed by FcConfigParse, the contents of the file(s) -will also be incorporated into the configuration by passing the filename(s) to -FcConfigLoadAndParse. If 'ignore_missing' is set to "yes" instead of the -default "no", a missing file or directory will elicit no warning message from -the library. - </para></refsect2> - <refsect2><title><literal><config></literal></title><para> -This element provides a place to consolidate additional configuration -information. <literal><config></literal> can contain <literal><blank></literal> and <literal><rescan></literal> elements in any -order. - </para></refsect2> - <refsect2><title><literal><blank></literal></title><para> -Fonts often include "broken" glyphs which appear in the encoding but are -drawn as blanks on the screen. Within the <literal><blank></literal> element, place each -Unicode characters which is supposed to be blank in an <literal><int></literal> element. -Characters outside of this set which are drawn as blank will be elided from -the set of characters supported by the font. - </para></refsect2> - <refsect2><title><literal><rescan></literal></title><para> -The <literal><rescan></literal> element holds an <literal><int></literal> element which indicates the default -interval between automatic checks for font configuration changes. -Fontconfig will validate all of the configuration files and directories and -automatically rebuild the internal datastructures when this interval passes. - </para></refsect2> - <refsect2><title><literal><selectfont></literal></title><para> -This element is used to black/white list fonts from being listed or matched -against. It holds acceptfont and rejectfont elements. - </para></refsect2> - <refsect2><title><literal><acceptfont></literal></title><para> -Fonts matched by an acceptfont element are "whitelisted"; such fonts are -explicitly included in the set of fonts used to resolve list and match -requests; including them in this list protects them from being "blacklisted" -by a rejectfont element. Acceptfont elements include glob and pattern -elements which are used to match fonts. - </para></refsect2> - <refsect2><title><literal><rejectfont></literal></title><para> -Fonts matched by an rejectfont element are "blacklisted"; such fonts are -excluded from the set of fonts used to resolve list and match requests as if -they didn't exist in the system. Rejectfont elements include glob and -pattern elements which are used to match fonts. - </para></refsect2> - <refsect2><title><literal><glob></literal></title><para> -Glob elements hold shell-style filename matching patterns (including ? and -*) which match fonts based on their complete pathnames. This can be used to -exclude a set of directories (/usr/share/fonts/uglyfont*), or particular -font file types (*.pcf.gz), but the latter mechanism relies rather heavily -on filenaming conventions which can't be relied upon. Note that globs -only apply to directories, not to individual fonts. - </para></refsect2> - <refsect2><title><literal><pattern></literal></title><para> -Pattern elements perform list-style matching on incoming fonts; that is, -they hold a list of elements and associated values. If all of those -elements have a matching value, then the pattern matches the font. This can -be used to select fonts based on attributes of the font (scalable, bold, -etc), which is a more reliable mechanism than using file extensions. -Pattern elements include patelt elements. - </para></refsect2> - <refsect2><title><literal><patelt name="property"></literal></title><para> -Patelt elements hold a single pattern element and list of values. They must -have a 'name' attribute which indicates the pattern element name. Patelt -elements include int, double, string, matrix, bool, charset and const -elements. - </para></refsect2> - <refsect2><title><literal><match target="pattern"></literal></title><para> -This element holds first a (possibly empty) list of <literal><test></literal> elements and then -a (possibly empty) list of <literal><edit></literal> elements. Patterns which match all of the -tests are subjected to all the edits. If 'target' is set to "font" instead -of the default "pattern", then this element applies to the font name -resulting from a match rather than a font pattern to be matched. If 'target' -is set to "scan", then this element applies when the font is scanned to -build the fontconfig database. - </para></refsect2> - <refsect2><title><literal><test qual="any" name="property" target="default" compare="eq"></literal></title><para> -This element contains a single value which is compared with the target -('pattern', 'font', 'scan' or 'default') property "property" (substitute any of the property names seen -above). 'compare' can be one of "eq", "not_eq", "less", "less_eq", "more", or -"more_eq". 'qual' may either be the default, "any", in which case the match -succeeds if any value associated with the property matches the test value, or -"all", in which case all of the values associated with the property must -match the test value. When used in a <match target="font"> element, -the target= attribute in the <test> element selects between matching -the original pattern or the font. "default" selects whichever target the -outer <match> element has selected. - </para></refsect2> - <refsect2><title><literal><edit name="property" mode="assign" binding="weak"></literal></title><para> -This element contains a list of expression elements (any of the value or -operator elements). The expression elements are evaluated at run-time and -modify the property "property". The modification depends on whether -"property" was matched by one of the associated <literal><test></literal> elements, if so, the -modification may affect the first matched value. Any values inserted into -the property are given the indicated binding ("strong", "weak" or "same") -with "same" binding using the value from the matched pattern element. -'mode' is one of: - <programlisting> - Mode With Match Without Match - --------------------------------------------------------------------- - "assign" Replace matching value Replace all values - "assign_replace" Replace all values Replace all values - "prepend" Insert before matching Insert at head of list - "prepend_first" Insert at head of list Insert at head of list - "append" Append after matching Append at end of list - "append_last" Append at end of list Append at end of list - </programlisting> - </para></refsect2> - <refsect2><title><literal><int></literal>, <literal><double></literal>, <literal><string></literal>, <literal><bool></literal></title><para> -These elements hold a single value of the indicated type. <literal><bool></literal> -elements hold either true or false. An important limitation exists in -the parsing of floating point numbers -- fontconfig requires that -the mantissa start with a digit, not a decimal point, so insert a leading -zero for purely fractional values (e.g. use 0.5 instead of .5 and -0.5 -instead of -.5). - </para></refsect2> - <refsect2><title><literal><matrix></literal></title><para> -This element holds the four <literal><double></literal> elements of an affine -transformation. - </para></refsect2> - <refsect2><title><literal><range></literal></title><para> -This element holds the two <literal><int></literal> elements of a range -representation. - </para></refsect2> - <refsect2><title><literal><charset></literal></title><para> -This element holds at least one <literal><int></literal> element of -an Unicode code point or more. - </para></refsect2> - <refsect2><title><literal><langset></literal></title><para> -This element holds at least one <literal><string></literal> element of -a RFC-3066-style languages or more. - </para></refsect2> - <refsect2><title><literal><name></literal></title><para> -Holds a property name. Evaluates to the first value from the property of -the font, not the pattern. - </para></refsect2> - <refsect2><title><literal><const></literal></title><para> -Holds the name of a constant; these are always integers and serve as -symbolic names for common font values: - <programlisting> - Constant Property Value - ------------------------------------- - thin weight 0 - extralight weight 40 - ultralight weight 40 - light weight 50 - book weight 75 - regular weight 80 - normal weight 80 - medium weight 100 - demibold weight 180 - semibold weight 180 - bold weight 200 - extrabold weight 205 - black weight 210 - heavy weight 210 - roman slant 0 - italic slant 100 - oblique slant 110 - ultracondensed width 50 - extracondensed width 63 - condensed width 75 - semicondensed width 87 - normal width 100 - semiexpanded width 113 - expanded width 125 - extraexpanded width 150 - ultraexpanded width 200 - proportional spacing 0 - dual spacing 90 - mono spacing 100 - charcell spacing 110 - unknown rgba 0 - rgb rgba 1 - bgr rgba 2 - vrgb rgba 3 - vbgr rgba 4 - none rgba 5 - lcdnone lcdfilter 0 - lcddefault lcdfilter 1 - lcdlight lcdfilter 2 - lcdlegacy lcdfilter 3 - hintnone hintstyle 0 - hintslight hintstyle 1 - hintmedium hintstyle 2 - hintfull hintstyle 3 - </programlisting> - </para> - </refsect2> - <refsect2> - <title><literal><or></literal>, <literal><and></literal>, <literal><plus></literal>, <literal><minus></literal>, <literal><times></literal>, <literal><divide></literal></title> - <para> -These elements perform the specified operation on a list of expression -elements. <literal><or></literal> and <literal><and></literal> are boolean, not bitwise. - </para> - </refsect2> - <refsect2> - <title><literal><eq></literal>, <literal><not_eq></literal>, <literal><less></literal>, <literal><less_eq></literal>, <literal><more></literal>, <literal><more_eq></literal></title> - <para> -These elements compare two values, producing a boolean result. - </para></refsect2> - <refsect2><title><literal><not></literal></title><para> -Inverts the boolean sense of its one expression element - </para></refsect2> - <refsect2><title><literal><if></literal></title><para> -This element takes three expression elements; if the value of the first is -true, it produces the value of the second, otherwise it produces the value -of the third. - </para></refsect2> - <refsect2><title><literal><alias></literal></title><para> -Alias elements provide a shorthand notation for the set of common match -operations needed to substitute one font family for another. They contain a -<literal><family></literal> element followed by optional <literal><prefer></literal>, <literal><accept></literal> and <literal><default></literal> -elements. Fonts matching the <literal><family></literal> element are edited to prepend the -list of <literal><prefer></literal>ed families before the matching <literal><family></literal>, append the -<literal><accept></literal>able families after the matching <literal><family></literal> and append the <literal><default></literal> -families to the end of the family list. - </para></refsect2> - <refsect2><title><literal><family></literal></title><para> -Holds a single font family name - </para></refsect2> - <refsect2><title><literal><prefer></literal>, <literal><accept></literal>, <literal><default></literal></title><para> -These hold a list of <literal><family></literal> elements to be used by the <literal><alias></literal> element. - </para></refsect2> -</refsect1> -<refsect1><title>EXAMPLE CONFIGURATION FILE</title> - <refsect2><title>System configuration file</title> - <para> -This is an example of a system-wide configuration file - </para> - <programlisting> -<?xml version="1.0"?> -<!DOCTYPE fontconfig SYSTEM "fonts.dtd"> -<!-- &confdir;/fonts.conf file to configure system font access --> -<fontconfig> -<!-- - Find fonts in these directories ---> -<dir>/usr/share/fonts</dir> -<dir>/usr/X11R6/lib/X11/fonts</dir> - -<!-- - Accept deprecated 'mono' alias, replacing it with 'monospace' ---> -<match target="pattern"> - <test qual="any" name="family"><string>mono</string></test> - <edit name="family" mode="assign"><string>monospace</string></edit> -</match> - -<!-- - Names not including any well known alias are given 'sans' ---> -<match target="pattern"> - <test qual="all" name="family" mode="not_eq">sans</test> - <test qual="all" name="family" mode="not_eq">serif</test> - <test qual="all" name="family" mode="not_eq">monospace</test> - <edit name="family" mode="append_last"><string>sans</string></edit> -</match> - -<!-- - Load per-user customization file, but don't complain - if it doesn't exist ---> -<include ignore_missing="yes">~/.fonts.conf</include> - -<!-- - Load local customization files, but don't complain - if there aren't any ---> -<include ignore_missing="yes">conf.d</include> -<include ignore_missing="yes">local.conf</include> - -<!-- - Alias well known font names to available TrueType fonts. - These substitute TrueType faces for similar Type1 - faces to improve screen appearance. ---> -<alias> - <family>Times</family> - <prefer><family>Times New Roman</family></prefer> - <default><family>serif</family></default> -</alias> -<alias> - <family>Helvetica</family> - <prefer><family>Arial</family></prefer> - <default><family>sans</family></default> -</alias> -<alias> - <family>Courier</family> - <prefer><family>Courier New</family></prefer> - <default><family>monospace</family></default> -</alias> - -<!-- - Provide required aliases for standard names - Do these after the users configuration file so that - any aliases there are used preferentially ---> -<alias> - <family>serif</family> - <prefer><family>Times New Roman</family></prefer> -</alias> -<alias> - <family>sans</family> - <prefer><family>Arial</family></prefer> -</alias> -<alias> - <family>monospace</family> - <prefer><family>Andale Mono</family></prefer> -</alias> -</fontconfig> - </programlisting> - </refsect2> - <refsect2><title>User configuration file</title> - <para> -This is an example of a per-user configuration file that lives in -~/.fonts.conf - </para> - <programlisting> -<?xml version="1.0"?> -<!DOCTYPE fontconfig SYSTEM "fonts.dtd"> -<!-- ~/.fonts.conf for per-user font configuration --> -<fontconfig> - -<!-- - Private font directory ---> -<dir>~/.fonts</dir> - -<!-- - use rgb sub-pixel ordering to improve glyph appearance on - LCD screens. Changes affecting rendering, but not matching - should always use target="font". ---> -<match target="font"> - <edit name="rgba" mode="assign"><const>rgb</const></edit> -</match> -</fontconfig> - </programlisting> - </refsect2> -</refsect1> -<refsect1><title>Files</title> - <para> -<emphasis>fonts.conf</emphasis> -contains configuration information for the fontconfig library -consisting of directories to look at for font information as well as -instructions on editing program specified font patterns before attempting to -match the available fonts. It is in XML format. - </para> - <para> -<emphasis>conf.d</emphasis> -is the conventional name for a directory of additional configuration files -managed by external applications or the local administrator. The -filenames starting with decimal digits are sorted in lexicographic order -and used as additional configuration files. All of these files are in XML -format. The master fonts.conf file references this directory in an -<include> directive. - </para> - <para> -<emphasis>fonts.dtd</emphasis> -is a DTD that describes the format of the configuration files. - </para> - <para> -<emphasis>~/.fonts.conf.d</emphasis> -is the conventional name for a per-user directory of (typically -auto-generated) configuration files, although the -actual location is specified in the global fonts.conf file. - </para> - <para> -<emphasis>~/.fonts.conf</emphasis> -is the conventional location for per-user font configuration, although the -actual location is specified in the global fonts.conf file. - </para> - <para> -<emphasis> ~/.fonts.cache-*</emphasis> -is the conventional repository of font information that isn't found in the -per-directory caches. This file is automatically maintained by fontconfig. - </para> -</refsect1> -<refsect1><title>See Also</title> - <para> -fc-cat(1), fc-cache(1), fc-list(1), fc-match(1), fc-query(1) - </para> -</refsect1> -<refsect1><title>Version</title> - <para> -Fontconfig version &version; - </para> -</refsect1> -</refentry> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V3.1//EN" [
+<!ENTITY version SYSTEM "version.sgml">
+<!ENTITY confdir SYSTEM "confdir.sgml">
+]>
+<!--
+ Copyright © 2003 Keith Packard
+
+ Permission to use, copy, modify, distribute, and sell this software and its
+ documentation for any purpose is hereby granted without fee, provided that
+ the above copyright notice appear in all copies and that both that
+ copyright notice and this permission notice appear in supporting
+ documentation, and that the name of the author(s) not be used in
+ advertising or publicity pertaining to distribution of the software without
+ specific, written prior permission. The authors make no
+ representations about the suitability of this software for any purpose. It
+ is provided "as is" without express or implied warranty.
+
+ THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ PERFORMANCE OF THIS SOFTWARE.
+-->
+<refentry>
+<refmeta>
+ <refentrytitle>fonts-conf</refentrytitle>
+ <manvolnum>5</manvolnum>
+</refmeta>
+<refnamediv>
+ <refname>fonts.conf</refname>
+ <refpurpose>Font configuration files</refpurpose>
+</refnamediv>
+<refsynopsisdiv>
+<synopsis>
+ &confdir;/fonts.conf
+ &confdir;/fonts.dtd
+ &confdir;/conf.d
+ ~/.fonts.conf.d
+ ~/.fonts.conf
+</synopsis>
+</refsynopsisdiv>
+<refsect1><title>Description</title>
+ <para>
+Fontconfig is a library designed to provide system-wide font configuration,
+customization and application access.
+ </para>
+</refsect1>
+<refsect1><title>Functional Overview</title>
+ <para>
+Fontconfig contains two essential modules, the configuration module which
+builds an internal configuration from XML files and the matching module
+which accepts font patterns and returns the nearest matching font.
+ </para>
+ <refsect2><title>Font Configuration</title>
+ <para>
+The configuration module consists of the FcConfig datatype, libexpat and
+FcConfigParse which walks over an XML tree and amends a configuration with
+data found within. From an external perspective, configuration of the
+library consists of generating a valid XML tree and feeding that to
+FcConfigParse. The only other mechanism provided to applications for
+changing the running configuration is to add fonts and directories to the
+list of application-provided font files.
+ </para><para>
+The intent is to make font configurations relatively static, and shared by
+as many applications as possible. It is hoped that this will lead to more
+stable font selection when passing names from one application to another.
+XML was chosen as a configuration file format because it provides a format
+which is easy for external agents to edit while retaining the correct
+structure and syntax.
+ </para><para>
+Font configuration is separate from font matching; applications needing to
+do their own matching can access the available fonts from the library and
+perform private matching. The intent is to permit applications to pick and
+choose appropriate functionality from the library instead of forcing them to
+choose between this library and a private configuration mechanism. The hope
+is that this will ensure that configuration of fonts for all applications
+can be centralized in one place. Centralizing font configuration will
+simplify and regularize font installation and customization.
+ </para>
+ </refsect2>
+ <refsect2>
+ <title>Font Properties</title>
+ <para>
+While font patterns may contain essentially any properties, there are some
+well known properties with associated types. Fontconfig uses some of these
+properties for font matching and font completion. Others are provided as a
+convenience for the applications' rendering mechanism.
+ </para>
+ <programlisting>
+ Property Type Description
+ --------------------------------------------------------------
+ family String Font family names
+ familylang String Languages corresponding to each family
+ style String Font style. Overrides weight and slant
+ stylelang String Languages corresponding to each style
+ fullname String Font full names (often includes style)
+ fullnamelang String Languages corresponding to each fullname
+ slant Int Italic, oblique or roman
+ weight Int Light, medium, demibold, bold or black
+ size Double Point size
+ width Int Condensed, normal or expanded
+ aspect Double Stretches glyphs horizontally before hinting
+ pixelsize Double Pixel size
+ spacing Int Proportional, dual-width, monospace or charcell
+ foundry String Font foundry name
+ antialias Bool Whether glyphs can be antialiased
+ hinting Bool Whether the rasterizer should use hinting
+ hintstyle Int Automatic hinting style
+ verticallayout Bool Use vertical layout
+ autohint Bool Use autohinter instead of normal hinter
+ globaladvance Bool Use font global advance data
+ file String The filename holding the font
+ index Int The index of the font within the file
+ ftface FT_Face Use the specified FreeType face object
+ rasterizer String Which rasterizer is in use
+ outline Bool Whether the glyphs are outlines
+ scalable Bool Whether glyphs can be scaled
+ scale Double Scale factor for point->pixel conversions
+ dpi Double Target dots per inch
+ rgba Int unknown, rgb, bgr, vrgb, vbgr,
+ none - subpixel geometry
+ lcdfilter Int Type of LCD filter
+ minspace Bool Eliminate leading from line spacing
+ charset CharSet Unicode chars encoded by the font
+ lang String List of RFC-3066-style languages this
+ font supports
+ fontversion Int Version number of the font
+ capability String List of layout capabilities in the font
+ embolden Bool Rasterizer should synthetically embolden the font
+ </programlisting>
+ </refsect2>
+ <refsect2>
+ <title>Font Matching</title>
+ <para>
+Fontconfig performs matching by measuring the distance from a provided
+pattern to all of the available fonts in the system. The closest matching
+font is selected. This ensures that a font will always be returned, but
+doesn't ensure that it is anything like the requested pattern.
+ </para><para>
+Font matching starts with an application constructed pattern. The desired
+attributes of the resulting font are collected together in a pattern. Each
+property of the pattern can contain one or more values; these are listed in
+priority order; matches earlier in the list are considered "closer" than
+matches later in the list.
+ </para><para>
+The initial pattern is modified by applying the list of editing instructions
+specific to patterns found in the configuration; each consists of a match
+predicate and a set of editing operations. They are executed in the order
+they appeared in the configuration. Each match causes the associated
+sequence of editing operations to be applied.
+ </para><para>
+After the pattern has been edited, a sequence of default substitutions are
+performed to canonicalize the set of available properties; this avoids the
+need for the lower layers to constantly provide default values for various
+font properties during rendering.
+ </para><para>
+The canonical font pattern is finally matched against all available fonts.
+The distance from the pattern to the font is measured for each of several
+properties: foundry, charset, family, lang, spacing, pixelsize, style,
+slant, weight, antialias, rasterizer and outline. This list is in priority
+order -- results of comparing earlier elements of this list weigh more
+heavily than later elements.
+ </para><para>
+There is one special case to this rule; family names are split into two
+bindings; strong and weak. Strong family names are given greater precedence
+in the match than lang elements while weak family names are given lower
+precedence than lang elements. This permits the document language to drive
+font selection when any document specified font is unavailable.
+ </para><para>
+The pattern representing that font is augmented to include any properties
+found in the pattern but not found in the font itself; this permits the
+application to pass rendering instructions or any other data through the
+matching system. Finally, the list of editing instructions specific to
+fonts found in the configuration are applied to the pattern. This modified
+pattern is returned to the application.
+ </para><para>
+The return value contains sufficient information to locate and rasterize the
+font, including the file name, pixel size and other rendering data. As
+none of the information involved pertains to the FreeType library,
+applications are free to use any rasterization engine or even to take
+the identified font file and access it directly.
+ </para><para>
+The match/edit sequences in the configuration are performed in two passes
+because there are essentially two different operations necessary -- the
+first is to modify how fonts are selected; aliasing families and adding
+suitable defaults. The second is to modify how the selected fonts are
+rasterized. Those must apply to the selected font, not the original pattern
+as false matches will often occur.
+ </para>
+ </refsect2>
+ <refsect2><title>Font Names</title>
+ <para>
+Fontconfig provides a textual representation for patterns that the library
+can both accept and generate. The representation is in three parts, first a
+list of family names, second a list of point sizes and finally a list of
+additional properties:
+ </para>
+ <programlisting>
+ <families>-<point sizes>:<name1>=<values1>:<name2>=<values2>...
+ </programlisting>
+ <para>
+Values in a list are separated with commas. The name needn't include either
+families or point sizes; they can be elided. In addition, there are
+symbolic constants that simultaneously indicate both a name and a value.
+Here are some examples:
+ </para>
+ <programlisting>
+ Name Meaning
+ ----------------------------------------------------------
+ Times-12 12 point Times Roman
+ Times-12:bold 12 point Times Bold
+ Courier:italic Courier Italic in the default size
+ Monospace:matrix=1 .1 0 1 The users preferred monospace font
+ with artificial obliquing
+ </programlisting>
+ <para>
+The '\', '-', ':' and ',' characters in family names must be preceded by a
+'\' character to avoid having them misinterpreted. Similarly, values
+containing '\', '=', '_', ':' and ',' must also have them preceded by a
+'\' character. The '\' characters are stripped out of the family name and
+values as the font name is read.
+ </para>
+ </refsect2>
+</refsect1>
+<refsect1><title>Debugging Applications</title>
+ <para>
+To help diagnose font and applications problems, fontconfig is built with a
+large amount of internal debugging left enabled. It is controlled by means
+of the FC_DEBUG environment variable. The value of this variable is
+interpreted as a number, and each bit within that value controls different
+debugging messages.
+ </para>
+ <programlisting>
+ Name Value Meaning
+ ---------------------------------------------------------
+ MATCH 1 Brief information about font matching
+ MATCHV 2 Extensive font matching information
+ EDIT 4 Monitor match/test/edit execution
+ FONTSET 8 Track loading of font information at startup
+ CACHE 16 Watch cache files being written
+ CACHEV 32 Extensive cache file writing information
+ PARSE 64 (no longer in use)
+ SCAN 128 Watch font files being scanned to build caches
+ SCANV 256 Verbose font file scanning information
+ MEMORY 512 Monitor fontconfig memory usage
+ CONFIG 1024 Monitor which config files are loaded
+ LANGSET 2048 Dump char sets used to construct lang values
+ OBJTYPES 4096 Display message when value typechecks fail
+ </programlisting>
+ <para>
+Add the value of the desired debug levels together and assign that (in
+base 10) to the FC_DEBUG environment variable before running the
+application. Output from these statements is sent to stdout.
+ </para>
+</refsect1>
+<refsect1><title>Lang Tags</title>
+ <para>
+Each font in the database contains a list of languages it supports. This is
+computed by comparing the Unicode coverage of the font with the orthography
+of each language. Languages are tagged using an RFC-3066 compatible naming
+and occur in two parts -- the ISO 639 language tag followed a hyphen and then
+by the ISO 3166 country code. The hyphen and country code may be elided.
+ </para><para>
+Fontconfig has orthographies for several languages built into the library.
+No provision has been made for adding new ones aside from rebuilding the
+library. It currently supports 122 of the 139 languages named in ISO 639-1,
+141 of the languages with two-letter codes from ISO 639-2 and another 30
+languages with only three-letter codes. Languages with both two and three
+letter codes are provided with only the two letter code.
+ </para><para>
+For languages used in multiple territories with radically different
+character sets, fontconfig includes per-territory orthographies. This
+includes Azerbaijani, Kurdish, Pashto, Tigrinya and Chinese.
+ </para>
+</refsect1>
+<refsect1><title>Configuration File Format</title>
+ <para>
+Configuration files for fontconfig are stored in XML format; this
+format makes external configuration tools easier to write and ensures that
+they will generate syntactically correct configuration files. As XML
+files are plain text, they can also be manipulated by the expert user using
+a text editor.
+ </para><para>
+The fontconfig document type definition resides in the external entity
+"fonts.dtd"; this is normally stored in the default font configuration
+directory (&confdir;). Each configuration file should contain the
+following structure:
+ <programlisting>
+ <?xml version="1.0"?>
+ <!DOCTYPE fontconfig SYSTEM "fonts.dtd">
+ <fontconfig>
+ ...
+ </fontconfig>
+ </programlisting>
+ </para>
+<refsect2><title><literal><fontconfig></literal></title><para>
+This is the top level element for a font configuration and can contain
+<literal><dir></literal>, <literal><cache></literal>, <literal><include></literal>, <literal><match></literal> and <literal><alias></literal> elements in any order.
+ </para></refsect2>
+ <refsect2><title><literal><dir></literal></title><para>
+This element contains a directory name which will be scanned for font files
+to include in the set of available fonts.
+ </para></refsect2>
+ <refsect2><title><literal><cache></literal></title><para>
+This element contains a file name for the per-user cache of font
+information. If it starts with '~', it refers to a file in the users
+home directory. This file is used to hold information about fonts that
+isn't present in the per-directory cache files. It is automatically
+maintained by the fontconfig library. The default for this file
+is ``~/.fonts.cache-<literal><version></literal>'', where <literal><version></literal> is the font configuration
+file version number (currently 2).
+ </para></refsect2>
+ <refsect2><title><literal><include ignore_missing="no"></literal></title><para>
+This element contains the name of an additional configuration file or
+directory. If a directory, every file within that directory starting with an
+ASCII digit (U+0030 - U+0039) and ending with the string ``.conf'' will be processed in sorted order. When
+the XML datatype is traversed by FcConfigParse, the contents of the file(s)
+will also be incorporated into the configuration by passing the filename(s) to
+FcConfigLoadAndParse. If 'ignore_missing' is set to "yes" instead of the
+default "no", a missing file or directory will elicit no warning message from
+the library.
+ </para></refsect2>
+ <refsect2><title><literal><config></literal></title><para>
+This element provides a place to consolidate additional configuration
+information. <literal><config></literal> can contain <literal><blank></literal> and <literal><rescan></literal> elements in any
+order.
+ </para></refsect2>
+ <refsect2><title><literal><blank></literal></title><para>
+Fonts often include "broken" glyphs which appear in the encoding but are
+drawn as blanks on the screen. Within the <literal><blank></literal> element, place each
+Unicode characters which is supposed to be blank in an <literal><int></literal> element.
+Characters outside of this set which are drawn as blank will be elided from
+the set of characters supported by the font.
+ </para></refsect2>
+ <refsect2><title><literal><rescan></literal></title><para>
+The <literal><rescan></literal> element holds an <literal><int></literal> element which indicates the default
+interval between automatic checks for font configuration changes.
+Fontconfig will validate all of the configuration files and directories and
+automatically rebuild the internal datastructures when this interval passes.
+ </para></refsect2>
+ <refsect2><title><literal><selectfont></literal></title><para>
+This element is used to black/white list fonts from being listed or matched
+against. It holds acceptfont and rejectfont elements.
+ </para></refsect2>
+ <refsect2><title><literal><acceptfont></literal></title><para>
+Fonts matched by an acceptfont element are "whitelisted"; such fonts are
+explicitly included in the set of fonts used to resolve list and match
+requests; including them in this list protects them from being "blacklisted"
+by a rejectfont element. Acceptfont elements include glob and pattern
+elements which are used to match fonts.
+ </para></refsect2>
+ <refsect2><title><literal><rejectfont></literal></title><para>
+Fonts matched by an rejectfont element are "blacklisted"; such fonts are
+excluded from the set of fonts used to resolve list and match requests as if
+they didn't exist in the system. Rejectfont elements include glob and
+pattern elements which are used to match fonts.
+ </para></refsect2>
+ <refsect2><title><literal><glob></literal></title><para>
+Glob elements hold shell-style filename matching patterns (including ? and
+*) which match fonts based on their complete pathnames. This can be used to
+exclude a set of directories (/usr/share/fonts/uglyfont*), or particular
+font file types (*.pcf.gz), but the latter mechanism relies rather heavily
+on filenaming conventions which can't be relied upon. Note that globs
+only apply to directories, not to individual fonts.
+ </para></refsect2>
+ <refsect2><title><literal><pattern></literal></title><para>
+Pattern elements perform list-style matching on incoming fonts; that is,
+they hold a list of elements and associated values. If all of those
+elements have a matching value, then the pattern matches the font. This can
+be used to select fonts based on attributes of the font (scalable, bold,
+etc), which is a more reliable mechanism than using file extensions.
+Pattern elements include patelt elements.
+ </para></refsect2>
+ <refsect2><title><literal><patelt name="property"></literal></title><para>
+Patelt elements hold a single pattern element and list of values. They must
+have a 'name' attribute which indicates the pattern element name. Patelt
+elements include int, double, string, matrix, bool, charset and const
+elements.
+ </para></refsect2>
+ <refsect2><title><literal><match target="pattern"></literal></title><para>
+This element holds first a (possibly empty) list of <literal><test></literal> elements and then
+a (possibly empty) list of <literal><edit></literal> elements. Patterns which match all of the
+tests are subjected to all the edits. If 'target' is set to "font" instead
+of the default "pattern", then this element applies to the font name
+resulting from a match rather than a font pattern to be matched. If 'target'
+is set to "scan", then this element applies when the font is scanned to
+build the fontconfig database.
+ </para></refsect2>
+ <refsect2><title><literal><test qual="any" name="property" target="default" compare="eq"></literal></title><para>
+This element contains a single value which is compared with the target
+('pattern', 'font', 'scan' or 'default') property "property" (substitute any of the property names seen
+above). 'compare' can be one of "eq", "not_eq", "less", "less_eq", "more", or
+"more_eq". 'qual' may either be the default, "any", in which case the match
+succeeds if any value associated with the property matches the test value, or
+"all", in which case all of the values associated with the property must
+match the test value. When used in a <match target="font"> element,
+the target= attribute in the <test> element selects between matching
+the original pattern or the font. "default" selects whichever target the
+outer <match> element has selected.
+ </para></refsect2>
+ <refsect2><title><literal><edit name="property" mode="assign" binding="weak"></literal></title><para>
+This element contains a list of expression elements (any of the value or
+operator elements). The expression elements are evaluated at run-time and
+modify the property "property". The modification depends on whether
+"property" was matched by one of the associated <literal><test></literal> elements, if so, the
+modification may affect the first matched value. Any values inserted into
+the property are given the indicated binding ("strong", "weak" or "same")
+with "same" binding using the value from the matched pattern element.
+'mode' is one of:
+ <programlisting>
+ Mode With Match Without Match
+ ---------------------------------------------------------------------
+ "assign" Replace matching value Replace all values
+ "assign_replace" Replace all values Replace all values
+ "prepend" Insert before matching Insert at head of list
+ "prepend_first" Insert at head of list Insert at head of list
+ "append" Append after matching Append at end of list
+ "append_last" Append at end of list Append at end of list
+ </programlisting>
+ </para></refsect2>
+ <refsect2><title><literal><int></literal>, <literal><double></literal>, <literal><string></literal>, <literal><bool></literal></title><para>
+These elements hold a single value of the indicated type. <literal><bool></literal>
+elements hold either true or false. An important limitation exists in
+the parsing of floating point numbers -- fontconfig requires that
+the mantissa start with a digit, not a decimal point, so insert a leading
+zero for purely fractional values (e.g. use 0.5 instead of .5 and -0.5
+instead of -.5).
+ </para></refsect2>
+ <refsect2><title><literal><matrix></literal></title><para>
+This element holds the four <literal><double></literal> elements of an affine
+transformation.
+ </para></refsect2>
+ <refsect2><title><literal><range></literal></title><para>
+This element holds the two <literal><int></literal> elements of a range
+representation.
+ </para></refsect2>
+ <refsect2><title><literal><charset></literal></title><para>
+This element holds at least one <literal><int></literal> element of
+an Unicode code point or more.
+ </para></refsect2>
+ <refsect2><title><literal><langset></literal></title><para>
+This element holds at least one <literal><string></literal> element of
+a RFC-3066-style languages or more.
+ </para></refsect2>
+ <refsect2><title><literal><name></literal></title><para>
+Holds a property name. Evaluates to the first value from the property of
+the font, not the pattern.
+ </para></refsect2>
+ <refsect2><title><literal><const></literal></title><para>
+Holds the name of a constant; these are always integers and serve as
+symbolic names for common font values:
+ <programlisting>
+ Constant Property Value
+ -------------------------------------
+ thin weight 0
+ extralight weight 40
+ ultralight weight 40
+ light weight 50
+ book weight 75
+ regular weight 80
+ normal weight 80
+ medium weight 100
+ demibold weight 180
+ semibold weight 180
+ bold weight 200
+ extrabold weight 205
+ black weight 210
+ heavy weight 210
+ roman slant 0
+ italic slant 100
+ oblique slant 110
+ ultracondensed width 50
+ extracondensed width 63
+ condensed width 75
+ semicondensed width 87
+ normal width 100
+ semiexpanded width 113
+ expanded width 125
+ extraexpanded width 150
+ ultraexpanded width 200
+ proportional spacing 0
+ dual spacing 90
+ mono spacing 100
+ charcell spacing 110
+ unknown rgba 0
+ rgb rgba 1
+ bgr rgba 2
+ vrgb rgba 3
+ vbgr rgba 4
+ none rgba 5
+ lcdnone lcdfilter 0
+ lcddefault lcdfilter 1
+ lcdlight lcdfilter 2
+ lcdlegacy lcdfilter 3
+ hintnone hintstyle 0
+ hintslight hintstyle 1
+ hintmedium hintstyle 2
+ hintfull hintstyle 3
+ </programlisting>
+ </para>
+ </refsect2>
+ <refsect2>
+ <title><literal><or></literal>, <literal><and></literal>, <literal><plus></literal>, <literal><minus></literal>, <literal><times></literal>, <literal><divide></literal></title>
+ <para>
+These elements perform the specified operation on a list of expression
+elements. <literal><or></literal> and <literal><and></literal> are boolean, not bitwise.
+ </para>
+ </refsect2>
+ <refsect2>
+ <title><literal><eq></literal>, <literal><not_eq></literal>, <literal><less></literal>, <literal><less_eq></literal>, <literal><more></literal>, <literal><more_eq></literal></title>
+ <para>
+These elements compare two values, producing a boolean result.
+ </para></refsect2>
+ <refsect2><title><literal><not></literal></title><para>
+Inverts the boolean sense of its one expression element
+ </para></refsect2>
+ <refsect2><title><literal><if></literal></title><para>
+This element takes three expression elements; if the value of the first is
+true, it produces the value of the second, otherwise it produces the value
+of the third.
+ </para></refsect2>
+ <refsect2><title><literal><alias></literal></title><para>
+Alias elements provide a shorthand notation for the set of common match
+operations needed to substitute one font family for another. They contain a
+<literal><family></literal> element followed by optional <literal><prefer></literal>, <literal><accept></literal> and <literal><default></literal>
+elements. Fonts matching the <literal><family></literal> element are edited to prepend the
+list of <literal><prefer></literal>ed families before the matching <literal><family></literal>, append the
+<literal><accept></literal>able families after the matching <literal><family></literal> and append the <literal><default></literal>
+families to the end of the family list.
+ </para></refsect2>
+ <refsect2><title><literal><family></literal></title><para>
+Holds a single font family name
+ </para></refsect2>
+ <refsect2><title><literal><prefer></literal>, <literal><accept></literal>, <literal><default></literal></title><para>
+These hold a list of <literal><family></literal> elements to be used by the <literal><alias></literal> element.
+ </para></refsect2>
+</refsect1>
+<refsect1><title>EXAMPLE CONFIGURATION FILE</title>
+ <refsect2><title>System configuration file</title>
+ <para>
+This is an example of a system-wide configuration file
+ </para>
+ <programlisting>
+<?xml version="1.0"?>
+<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
+<!-- &confdir;/fonts.conf file to configure system font access -->
+<fontconfig>
+<!--
+ Find fonts in these directories
+-->
+<dir>/usr/share/fonts</dir>
+<dir>/usr/X11R6/lib/X11/fonts</dir>
+
+<!--
+ Accept deprecated 'mono' alias, replacing it with 'monospace'
+-->
+<match target="pattern">
+ <test qual="any" name="family"><string>mono</string></test>
+ <edit name="family" mode="assign"><string>monospace</string></edit>
+</match>
+
+<!--
+ Names not including any well known alias are given 'sans'
+-->
+<match target="pattern">
+ <test qual="all" name="family" mode="not_eq">sans</test>
+ <test qual="all" name="family" mode="not_eq">serif</test>
+ <test qual="all" name="family" mode="not_eq">monospace</test>
+ <edit name="family" mode="append_last"><string>sans</string></edit>
+</match>
+
+<!--
+ Load per-user customization file, but don't complain
+ if it doesn't exist
+-->
+<include ignore_missing="yes">~/.fonts.conf</include>
+
+<!--
+ Load local customization files, but don't complain
+ if there aren't any
+-->
+<include ignore_missing="yes">conf.d</include>
+<include ignore_missing="yes">local.conf</include>
+
+<!--
+ Alias well known font names to available TrueType fonts.
+ These substitute TrueType faces for similar Type1
+ faces to improve screen appearance.
+-->
+<alias>
+ <family>Times</family>
+ <prefer><family>Times New Roman</family></prefer>
+ <default><family>serif</family></default>
+</alias>
+<alias>
+ <family>Helvetica</family>
+ <prefer><family>Arial</family></prefer>
+ <default><family>sans</family></default>
+</alias>
+<alias>
+ <family>Courier</family>
+ <prefer><family>Courier New</family></prefer>
+ <default><family>monospace</family></default>
+</alias>
+
+<!--
+ Provide required aliases for standard names
+ Do these after the users configuration file so that
+ any aliases there are used preferentially
+-->
+<alias>
+ <family>serif</family>
+ <prefer><family>Times New Roman</family></prefer>
+</alias>
+<alias>
+ <family>sans</family>
+ <prefer><family>Arial</family></prefer>
+</alias>
+<alias>
+ <family>monospace</family>
+ <prefer><family>Andale Mono</family></prefer>
+</alias>
+</fontconfig>
+ </programlisting>
+ </refsect2>
+ <refsect2><title>User configuration file</title>
+ <para>
+This is an example of a per-user configuration file that lives in
+~/.fonts.conf
+ </para>
+ <programlisting>
+<?xml version="1.0"?>
+<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
+<!-- ~/.fonts.conf for per-user font configuration -->
+<fontconfig>
+
+<!--
+ Private font directory
+-->
+<dir>~/.fonts</dir>
+
+<!--
+ use rgb sub-pixel ordering to improve glyph appearance on
+ LCD screens. Changes affecting rendering, but not matching
+ should always use target="font".
+-->
+<match target="font">
+ <edit name="rgba" mode="assign"><const>rgb</const></edit>
+</match>
+</fontconfig>
+ </programlisting>
+ </refsect2>
+</refsect1>
+<refsect1><title>Files</title>
+ <para>
+<emphasis>fonts.conf</emphasis>
+contains configuration information for the fontconfig library
+consisting of directories to look at for font information as well as
+instructions on editing program specified font patterns before attempting to
+match the available fonts. It is in XML format.
+ </para>
+ <para>
+<emphasis>conf.d</emphasis>
+is the conventional name for a directory of additional configuration files
+managed by external applications or the local administrator. The
+filenames starting with decimal digits are sorted in lexicographic order
+and used as additional configuration files. All of these files are in XML
+format. The master fonts.conf file references this directory in an
+<include> directive.
+ </para>
+ <para>
+<emphasis>fonts.dtd</emphasis>
+is a DTD that describes the format of the configuration files.
+ </para>
+ <para>
+<emphasis>~/.fonts.conf.d</emphasis>
+is the conventional name for a per-user directory of (typically
+auto-generated) configuration files, although the
+actual location is specified in the global fonts.conf file.
+ </para>
+ <para>
+<emphasis>~/.fonts.conf</emphasis>
+is the conventional location for per-user font configuration, although the
+actual location is specified in the global fonts.conf file.
+ </para>
+ <para>
+<emphasis> ~/.fonts.cache-*</emphasis>
+is the conventional repository of font information that isn't found in the
+per-directory caches. This file is automatically maintained by fontconfig.
+ </para>
+</refsect1>
+<refsect1><title>See Also</title>
+ <para>
+fc-cat(1), fc-cache(1), fc-list(1), fc-match(1), fc-query(1)
+ </para>
+</refsect1>
+<refsect1><title>Version</title>
+ <para>
+Fontconfig version &version;
+ </para>
+</refsect1>
+</refentry>
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