FONTS-CONF(5)                                                    FONTS-CONF(5)

       fonts.conf - Font configuration files


       Fontconfig is a library designed to provide system-wide font
       configuration, customization and application access.

       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

       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.

       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.

       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.

       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.

         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
         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

       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

       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.

       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

       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.

       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.

       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

       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.

       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.

       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.

       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:

            <families>-<point sizes>:<name1>=<values1>:<name2>=<values2>...

       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:

         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

       The '\', '-', ':' and ',' characters in family names must be preceeded
       by a '\' character to avoid having them misinterpreted. Similarly,
       values containing '\', '=', '_', ':' and ',' must also have them
       preceeded by a '\' character. The '\' characters are stripped out of
       the family name and values as the font name is read.

       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.

         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

       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.

       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.

       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.

       For languages used in multiple territories with radically different
       character sets, fontconfig includes per-territory orthographies.  This
       includes Azerbaijani, Kurdish, Pashto, Tigrinya and Chinese.

       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.

       The fontconfig document type definition resides in the external entity
       "fonts.dtd"; this is normally stored in the default font configuration
       directory (/etc/fonts).  Each configuration file should contain the
       following structure:

            <?xml version="1.0"?>
            <!DOCTYPE fontconfig SYSTEM "fonts.dtd">

       This is the top level element for a font configuration and can contain
       <dir>, <cache>, <include>, <match> and <alias> elements in any order.

       This element contains a directory name which will be scanned for font
       files to include in the set of available fonts.

       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-<version>'', where <version> is the font configuration
       file version number (currently 2).

       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.

       This element provides a place to consolidate additional configuration
       information.  <config> can contain <blank> and <rescan> elements in any

       Fonts often include "broken" glyphs which appear in the encoding but
       are drawn as blanks on the screen.  Within the <blank> element, place
       each Unicode characters which is supposed to be blank in an <int>
       element.  Characters outside of this set which are drawn as blank will
       be elided from the set of characters supported by the font.

       The <rescan> element holds an <int> 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.

       This element is used to black/white list fonts from being listed or
       matched against.  It holds acceptfont and rejectfont elements.

       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.

       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.

       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

       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.

       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.

       This element holds first a (possibly empty) list of <test> elements and
       then a (possibly empty) list of <edit> 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.

       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.

       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 <test>
       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:

         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

       These elements hold a single value of the indicated type.  <bool>
       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).

       This element holds the four <double> elements of an affine

       Holds a property name.  Evaluates to the first value from the property
       of the font, not the pattern.

       Holds the name of a constant; these are always integers and serve as
       symbolic names for common font values:

         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
         hintnone        hintstyle       0
         hintslight      hintstyle       1
         hintmedium      hintstyle       2
         hintfull        hintstyle       3

   <OR>, <AND>, <PLUS>, <MINUS>, <TIMES>, <DIVIDE>
       These elements perform the specified operation on a list of expression
       elements.  <or> and <and> are boolean, not bitwise.

   <EQ>, <NOT_EQ>, <LESS>, <LESS_EQ>, <MORE>, <MORE_EQ>
       These elements compare two values, producing a boolean result.

       Inverts the boolean sense of its one expression element

       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.

       Alias elements provide a shorthand notation for the set of common match
       operations needed to substitute one font family for another.  They
       contain a <family> element followed by optional <prefer>, <accept> and
       <default> elements.  Fonts matching the <family> element are edited to
       prepend the list of <prefer>ed families before the matching <family>,
       append the <accept>able families after the matching <family> and append
       the <default> families to the end of the family list.

       Holds a single font family name

       These hold a list of <family> elements to be used by the <alias>

       This is an example of a system-wide configuration file

       <?xml version="1.0"?>
       <!DOCTYPE fontconfig SYSTEM "fonts.dtd">
       <!-- /etc/fonts/fonts.conf file to configure system font access -->
            Find fonts in these directories

            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>

            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>

            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.
            <prefer><family>Times New Roman</family></prefer>
            <prefer><family>Courier New</family></prefer>

            Provide required aliases for standard names
            Do these after the users configuration file so that
            any aliases there are used preferentially
            <prefer><family>Times New Roman</family></prefer>
            <prefer><family>Andale Mono</family></prefer>

       This is an example of a per-user configuration file that lives in

       <?xml version="1.0"?>
       <!DOCTYPE fontconfig SYSTEM "fonts.dtd">
       <!-- ~/.fonts.conf for per-user font configuration -->

            Private font directory

            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>

       fonts.conf 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.

       conf.d 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.

       fonts.dtd is a DTD that describes the format of the configuration

       ~/.fonts.conf is the conventional location for per-user font
       configuration, although the actual location is specified in the global
       fonts.conf file.

        ~/.fonts.cache-* is the conventional repository of font information
       that isn't found in the per-directory caches.  This file is
       automatically maintained by fontconfig.

       fc-cache(1), fc-match(1), fc-list(1)

       Fontconfig version 2.4.2

                               02 December 2006                  FONTS-CONF(5)