<root
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
          $XDG_CONFIG_HOME/fontconfig/conf.d
          $XDG_CONFIG_HOME/fontconfig/fonts.conf
          ~/.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 inter‐
       nal  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 applica‐
       tion-provided font files.

       The  intent is to make font configurations relatively static, and shared by as many appli‐
       cations 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 associated types. Fontconfig uses some of these properties for font match‐
       ing  and  font completion. Others are provided as a convenience for the applications' ren‐
       dering 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 (deprecated)
         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 (deprecated)
         outline         Bool    Whether the glyphs are outlines
         scalable        Bool    Whether glyphs can be scaled
         color           Bool    Whether any glyphs have color
         scale           Double  Scale factor for point->pixel conversions (deprecated)
         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
         fontformat      String  String name of the font format
         embolden        Bool    Rasterizer should synthetically embolden the font
         embeddedbitmap  Bool    Use the embedded bitmap instead of the outline
         decorative      Bool    Whether the style is a decorative variant
         fontfeatures    String  List of the feature tags in OpenType to be enabled
         namelang        String  Language name to be used for the default value of
                                 familylang, stylelang, and fullnamelang
         prgname         String  String  Name of the running program
         postscriptname  String  Font family name in PostScript

   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 edit‐
       ing 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 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 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, includ‐
       ing  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:

            -:=:=...

       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 simultane‐
       ously 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.

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.  Lan‐
       guages  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, font‐
       config 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 cor‐
       rect 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 configu‐
       ration file should contain the following structure:

            
            
            
       ...
            

   
       This is the top level element for a font configuration and can contain ,  ,
       ,  and  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 Spec‐
       ification 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 direc‐
       tory 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 direc‐
       tory is ``$XDG_CACHE_HOME/fontconfig'' and it  contains  the  cache  files  named  ``-.cache-'',  where    is the font configuration file
       version number (currently 5).

   
       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 incorpo‐
       rated 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. If 'prefix' is set to "xdg", the value in
       the  XDG_CONFIG_HOME environment variable 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.   can contain  and  elements in any order.

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

   
       The  element holds an  element which indicates the default  interval  between
       automatic checks for font configuration changes.  Fontconfig will validate all of the con‐
       figuration 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  ele‐
       ments 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  sys‐
       tem. 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 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 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  elements and then a (possibly
       empty) list of  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 ele‐
       ment 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  element, the target= attribute  in
       the    element  selects between matching the original pattern or the font. "default"
       selects whichever target the outer  element has selected.

   
       This element contains a list of expression elements (any of the  value  or  operator  ele‐
       ments).  The  expression elements are evaluated at run-time and modify the property "prop‐
       erty". The modification depends on whether "property" was matched by one of the associated
         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
         "delete"                Delete matching value   Delete all values
         "delete_all"            Delete all values       Delete all values

   , , , 
       These elements hold a single value of the indicated type.  elements hold either true
       or false. An important limitation exists in the parsing of floating point numbers -- font‐
       config  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 four numerical expressions of an affine transformation.  At their sim‐
       plest these will be four  elements but they can also be more involved expressions.

   
       This element holds the two  elements of a range representation.

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

   
       This element holds at least one  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  pat‐
       tern  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
         demilight       weight          55
         semilight       weight          55
         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

   , , , , , 
       These elements perform the specified operation on a list of expression elements.   and
        are boolean, not bitwise.

   , , , , , , , 
       Inverts the boolean sense of its one expression element

   
       This  element  takes three expression elements; if the value of the first is true, it pro‐
       duces 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  element followed by
       optional ,  and  elements. Fonts matching  the    element
       are edited to prepend the list of ed families before the matching , append
       the able families after the matching  and append the  families to
       the end of the family list.

   
       Holds a single font family name

   , , 
       These hold a list of  elements to be used by the  element.

EXAMPLE CONFIGURATION FILE
   SYSTEM CONFIGURATION FILE
       This is an example of a system-wide configuration file

       
       
       
       
       
       /usr/share/fonts
       /usr/X11R6/lib/X11/fonts

       
       
            mono
            monospace
       

       
       
            sans-serif
            serif
            monospace
            sans-serif
       

       
       fontconfig/fonts.conf

       
       conf.d
       local.conf

       
       
            Times
            Times New Roman
            serif
       
       
            Helvetica
            Arial
            sans
       
       
            Courier
            Courier New
            monospace
       

       
       
            serif
            Times New Roman
       
       
            sans
            Arial
       
       
            monospace
            Andale Mono
       

       <--
            The example of the requirements of OR operator;
            If the 'family' contains 'Courier New' OR 'Courier'
            add 'monospace' as the alternative
       -->
       
            
                 Courier New
            
            
                 monospace
            
       
       
            
                 Courier
            
            
                 monospace
            
       

       

   USER CONFIGURATION FILE
       This  is  an example of a per-user configuration file that lives in $XDG_CONFIG_HOME/font‐
       config/fonts.conf

       
       
       
       

       
       fonts

       
       
            rgb
       
       
       
            
            
                 zh
            
            
                 serif
            
            
                 WenQuanYi Zen Hei
            
       
       
       
            
                 ja
            
            
                 sans-serif
            
            
                 VL Gothic
            
       
       

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  for‐
       mat.

       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  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  configuration,  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 depre‐
       cated now. it will not be read by default in the future version.

ENVIRONMENT VARIABLES
       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 details.

       FONTCONFIG_USE_MMAP  is  used  to control the use of mmap(2) for the cache files if avail‐
       able. this take a boolean 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.

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

VERSION
       Fontconfig version 2.11.94

                                           02 6月 2015                              FONTS-CONF(5)

Go-to-top  




Designed by SanjuD(@ngineerbabu)