fonts-conf


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 configura-
       tion, 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  configura-
       tion  with  data found within. From an external perspective, configura-
       tion of the library consists of generating a valid XML tree and feeding
       that  to  FcConfigParse.  The only other mechanism provided to applica-
       tions for changing the running configuration is to add fonts and direc-
       tories 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 pro-
       vides  a format which is easy for external agents to edit while retain-
       ing 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  applica-
       tions  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 config-
       uration of fonts for all applications 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 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
         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 match-
       ing 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 con-
       sists 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 val-
       ues 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, pixel-
       ties found in the pattern but not found in the font itself;  this  per-
       mits  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 pat-
       tern. This modified pattern is returned to the application.

       The return value contains sufficient information to locate and  raster-
       ize  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, val-
       ues 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  con-
       trolled  by  means  of  the FC_DEBUG environment variable. The value of
         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 appli-
       cation. 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-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 FILE FORMAT
       Configuration files for fontconfig are stored in XML format; this  for-
       mat 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 fol-
       lowing structure:

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



   <FONTCONFIG>
       tained  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  warning
       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> ele-
       ment.  Characters 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 automatically rebuild the internal datastructures when this  inter-
       val 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
       "blacklisted" 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

   <PATELT NAME= PROPERTY">"
       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.

   <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" (substi-
       tute 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 tar-
       get= attribute in the <test> element selects between matching the orig-
       inal  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> ele-
       ments, 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> ele-
       ments hold either true or false. An important limitation exists in  the
       parsing  of floating point numbers -- fontconfig requires that the man-

   <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>
       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 con-
       tain 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.

   <FAMILY>
       Holds a single font family name

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

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
       -->
            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>

       <!--
       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 configu-
       ration files managed by external applications or the local  administra-
       tor.  The  filenames starting with decimal digits are sorted in lexico-
       graphic 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 configura-
       tion,  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  automati-
       cally 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)
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