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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

       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.

       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 exter‐
       nal 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  regu‐
       larize font installation and customization.

       While  font patterns may contain essentially any properties, there are some well known properties with associ‐
       ated types. Fontconfig uses some of these properties for font matching and font completion.  Others  are  pro‐
       vided 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
         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
         fontfeatures    String  List of the feature tags in OpenType to be enabled
         prgname         String  String  Name of the running program

       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.

       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 applied.

       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  compar‐
       ing 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 fam‐
       ily 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.

       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.
       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 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.

       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

       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

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

       This  is  the top level element for a font configuration and can contain <dir>, <cachedir>, <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.  If  'prefix' is set to "xdg", the value in the XDG_DATA_HOME environment variable will be added as the
       path prefix. please see XDG Base Directory Specification for more details.

       This element contains a directory name that is supposed to be stored or read the cache of font information. If
       multiple  elements  are  specified  in the configuration file, the directory that can be accessed first in the
       list will be used to store the cache files. If it starts with '~', it refers to a directory in the users  home
       directory.  If 'prefix' is set to "xdg", the value in the XDG_CACHE_HOME environment variable will be added as
       the path prefix. please see XDG Base Directory Specification for  more  details.   The  default  directory  is
       ``$XDG_CACHE_HOME/fontconfig'' and it contains the cache files named ``<hash value>-<architecture>.cache-<ver‐
       sion'', where <version> is the font configureation file version number (currently 3).

       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 warn‐
       ing  message from the library. If 'prefix' is set to "xdg", the value in the XDG_CONFIG_HOME environment vari‐
       able will be added as the path prefix. please see XDG Base Directory Specification for more details.

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

       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.  Charac‐
       ters  outside  of this set which are drawn as blank will be elided from the set of characters supported by the

       listed" by a rejectfont element. Acceptfont elements include glob and pattern elements which are used to match

       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 particu‐
       lar 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.

       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 mecha‐
       nism 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", "more_eq", "contains" or "not_contains". '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.
       'ignore-blanks'  takes  a  boolean  value.  if 'ignore-blanks' is set "true", any blanks in the string will be
       ignored on its comparison. this takes effects only when compare="eq" or  compare="not_eq".   When  used  in  a
       <match target="font"> element, the target= attribute in the <test> element selects between matching the origi‐
       nal 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

       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  four numerical expressions of an affine transformation.  At their simplest these will be
       four <double> elements but they can also be more involved expressions.

       This element holds the two <int> elements of a range representation.

       This element holds at least one <int> element of an Unicode code point or more.

       This element holds at least one <string> element of a RFC-3066-style languages or more.

       Holds a property name. Evaluates to the first value  from  the  property  of  the  pattern.  If  the  'target'
       attribute  is  not present, it will default to 'default', in which case the property is returned from the font
       pattern during a target="font" match, and to the pattern during a target="pattern" match.  The  attribute  can
       also  take  the  values 'font' or 'pattern' to explicitly choose which pattern to use. It is an error to use a
       target of 'font' in a match that has target="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
         lcdlight        lcdfilter       2
         lcdlegacy       lcdfilter       3
         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.

       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> fami‐
       lies 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> element.

       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">

            Load per-user customization file, but don't complain
            if it doesn't exist
       <include ignore_missing="yes" prefix="xdg">fontconfig/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>

       <match target="pattern">
            <test name="family" mode="eq">
            <edit name="family" mode="prepend">


       This is an example of a per-user configuration file that lives in $XDG_CONFIG_HOME/fontconfig/fonts.conf

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

            Private font directory
       <dir prefix="xdg">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>
            use WenQuanYi Zen Hei font when serif is requested for Chinese
                 If you don't want to use WenQuanYi Zen Hei font for zh-tw etc,
                 you can use zh-cn instead of zh.
                 Please note, even if you set zh-cn, it still matches zh.
                 if you don't like it, you can use compare="eq"
                 instead of compare="contains".
            <test name="lang" compare="contains">
            <test name="family">
            <edit name="family" mode="prepend">
                 <string>WenQuanYi Zen Hei</string>

            <edit name="family" mode="prepend">
                 <string>VL Gothic</string>

       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 applica‐
       tions 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 files.

       $XDG_CONFIG_HOME/fontconfig/conf.d  and  ~/.fonts.conf.d  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.  please  note  that ~/.fonts.conf.d is deprecated now. it will not be read by default in the
       future version.

       $XDG_CONFIG_HOME/fontconfig/fonts.conf and ~/.fonts.conf is the conventional location for per-user  font  con‐
       figuration,  although  the  actual  location  is  specified  in  the  global fonts.conf file. please note that
       ~/.fonts.conf is deprecated now. it will not be read by default in the future version.

       $XDG_CACHE_HOME/fontconfig/*.cache-* and  ~/.fontconfig/*.cache-*  is  the  conventional  repository  of  font
       information that isn't found in the per-directory caches. This file is automatically maintained by fontconfig.
       please note that ~/.fontconfig/*.cache-* is deprecated now. it will not be read by default in the future  ver‐

       FONTCONFIG_FILE is used to override the default configuration file.

       FONTCONFIG_PATH is used to override the default configuration directory.

       FC_DEBUG  is  used  to  output  the  detailed  debugging messages. see Debugging Applications section for more

       FONTCONFIG_USE_MMAP is used to control the use of mmap(2) for the cache files if available. this take a  bool‐
       ean value. fontconfig will checks if the cache files are stored on the filesystem that is safe to use mmap(2).
       explicitly setting this environment variable will causes skipping this check and enforce to  use  or  not  use
       mmap(2) anyway.

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

       Fontconfig version 2.10.95