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



NAME
       fonts.conf - Font configuration files

SYNOPSIS
          /etc/fonts/fonts.conf
          /etc/fonts/fonts.dtd
          /etc/fonts/conf.d
          ~/.fonts.conf.d
          ~/.fonts.conf


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

FUNCTIONAL OVERVIEW
       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.

   FONT CONFIGURATION
       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 applica-
       tions can be centralized in one place. Centralizing  font  configuration  will  simplify  and  regularize  font
       installation and customization.

   FONT PROPERTIES
       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 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
         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



   FONT MATCHING
       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 vari-
       ous 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  ear-
       lier 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.

       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.

   FONT NAMES
       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.

DEBUGGING APPLICATIONS
       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.

LANG TAGS
       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-let-
       ter 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 FILE FORMAT
       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">
            <fontconfig>
       ...
            </fontconfig>



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

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

   <CACHE>
       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).

   <INCLUDE IGNORE_MISSING= NO">"
       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.

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

   <BLANK>
       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
       font.

   <RESCAN>
       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 auto-
       matically rebuild the internal datastructures when this interval passes.

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

   <ACCEPTFONT>
       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  "black-
       listed"  by a rejectfont element. Acceptfont elements include glob and pattern elements which are used to match
       fonts.

   <REJECTFONT>
       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>
       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>
       Pattern elements perform list-style matching on incoming fonts; that is, they hold a list of elements and asso-
       ciated 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 NAME= PROPERTY">"
       Patelt elements hold a single pattern element and list of values. They must have a 'name' attribute which indi-
       cates  the  pattern  element name. Patelt elements include int, double, string, matrix, bool, charset and const
       elements.

   <MATCH TARGET= PATTERN">"
       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.

   <TEST QUAL= ANY" NAME="PROPERTY" TARGET="DEFAULT" COMPARE="EQ">"
       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  suc-
       ceeds if any value associated with the property matches the test value, or "all", in which case all of the val-
       ues 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.

   <EDIT NAME= PROPERTY" MODE="ASSIGN" BINDING="WEAK">"
       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



   <INT>, <DOUBLE>, <STRING>, <BOOL>
       These elements hold a single value of the indicated type. <bool> elements hold either true or false. An  impor-
       tant  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).

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

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

   <CONST>
       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
         lcdnone         lcdfilter       0
         lcddefault      lcdfilter       1
         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.

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

   <NOT>
       Inverts the boolean sense of its one expression element

   <IF>
       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>
       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.

   <FAMILY>
       Holds a single font family name

   <PREFER>, <ACCEPT>, <DEFAULT>
       These hold a list of <family> elements to be used by the <alias> element.

EXAMPLE CONFIGURATION FILE
   SYSTEM CONFIGURATION FILE
       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 -->
       <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>



   USER CONFIGURATION FILE
       This is an example of a per-user configuration file that lives in ~/.fonts.conf

       <?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>



FILES
       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.

       ~/.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.

       ~/.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.

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

VERSION
       Fontconfig version 2.8.0



                               18 November 2009                  FONTS-CONF(5)