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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 access.

       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.

       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.

       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
	 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

       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.

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

       To help diagnose font and applications problems, fontconfig is built with a  large  amount
       of  internal debugging left enabled. It is controlled by means of the FC_DEBUG environment
       variable. The value of this variable is interpreted as a number, and each bit within  that
       value controls different debugging messages.

	 Name	      Value    Meaning
	 MATCH		  1    Brief information about font matching
	 MATCHV 	  2    Extensive font matching information
	 EDIT		  4    Monitor match/test/edit execution
	 FONTSET	  8    Track loading of font information at startup
	 CACHE		 16    Watch cache files being written
	 CACHEV 	 32    Extensive cache file writing information
	 PARSE		 64    (no longer in use)
	 SCAN		128    Watch font files being scanned to build caches
	 SCANV		256    Verbose font file scanning information
	 MEMORY 	512    Monitor fontconfig memory usage
	 CONFIG        1024    Monitor which config files are loaded
	 LANGSET       2048    Dump char sets used to construct lang values
	 OBJTYPES      4096    Display message when value typechecks fail

       Add  the  value	of  the desired debug levels together and assign that (in base 10) to the
       FC_DEBUG environment variable before running the application. Output from these statements
       is sent to stdout.

       Each  font  in  the database contains a list of languages it supports. This is computed by
       comparing the Unicode coverage of the font with the orthography	of  each  language.  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  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:

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

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

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

       This element contains a file name for the per-user cache of font information. If it starts
       with  '~',  it  refers  to  a  file in the users home directory. This file is used to hold
       information about fonts that isn't present in the per-directory cache files. It	is  auto-
       matically   maintained	by   the  fontconfig  library.	The  default  for  this  file  is
       ``~/.fonts.cache-<version>'', where <version> is the font configuration file version  num-
       ber (currently 2).

       This  element  contains	the  name  of an additional configuration file or directory. If a
       directory, every file within that directory starting with an ASCII digit (U+0030 - U+0039)
       and  ending  with  the  string  ``.conf''  will be processed in sorted order. When the XML
       datatype is traversed by FcConfigParse, the contents of the file(s) will also be  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.

       This  element  provides a place to consolidate additional configuration information. <con-
       fig> 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.  Characters outside of this set which are drawn as  blank
       will be elided from the set of characters supported by the font.

       The  <rescan>  element holds an <int> element which indicates the default interval between
       automatic checks for font configuration changes.  Fontconfig will validate all of the 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 <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  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", 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  tar-
       get="font">  element, the target= attribute in the <test> element selects between matching
       the original pattern or the font. "default" selects whichever  target  the  outer  <match>
       element has selected.

       This  element  contains	a  list of expression elements (any of the value or operator 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
       <test> elements, if so, the modification may affect the first matched  value.  Any  values
       inserted  into  the  property are given the indicated binding ("strong", "weak" or "same")
       with "same" binding using the value from the matched pattern element.  'mode' is one of:

	 Mode			 With Match		 Without Match
	 "assign"		 Replace matching value  Replace all values
	 "assign_replace"	 Replace all values	 Replace all values
	 "prepend"		 Insert before matching  Insert at head of list
	 "prepend_first"	 Insert at head of list  Insert at head of list
	 "append"		 Append after matching	 Append at end of list
	 "append_last"		 Append at end of list	 Append at end of list

       These elements hold a single value of the indicated type. <bool> elements hold either true
       or false. An important limitation exists in the parsing of floating point numbers -- 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

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

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

       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.

       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 <family> element followed by
       optional <prefer>, <accept> and <default> elements. Fonts matching  the	<family>  element
       are edited to prepend the list of <prefer>ed families before the matching <family>, append
       the <accept>able families after the matching <family> and append the <default> families to
       the end of the family list.

       Holds a single font family name

       These hold a list of <family> elements to be used by the <alias> 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">
	    <test qual="any" name="family"><string>mono</string></test>
	    <edit name="family" mode="assign"><string>monospace</string></edit>

	    Names not including any well known alias are given 'sans'
       <match target="pattern">
	    <test qual="all" name="family" mode="not_eq">sans</test>
	    <test qual="all" name="family" mode="not_eq">serif</test>
	    <test qual="all" name="family" mode="not_eq">monospace</test>
	    <edit name="family" mode="append_last"><string>sans</string></edit>

	    Load per-user customization file, but don't complain
	    if it doesn't exist
       <include ignore_missing="yes">~/.fonts.conf</include>

	    Load local customization files, but don't complain
	    if there aren't any
       <include ignore_missing="yes">conf.d</include>
       <include ignore_missing="yes">local.conf</include>

	    Alias well known font names to available TrueType fonts.
	    These substitute TrueType faces for similar Type1
	    faces to improve screen appearance.
	    <prefer><family>Times New Roman</family></prefer>
	    <prefer><family>Courier New</family></prefer>

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

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

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

	    Private font directory

	    use rgb sub-pixel ordering to improve glyph appearance on
	    LCD screens.  Changes affecting rendering, but not matching
	    should always use target="font".
       <match target="font">
	    <edit name="rgba" mode="assign"><const>rgb</const></edit>

       fonts.conf  contains  configuration  information  for the fontconfig library consisting of
       directories to look at for font information as well as  instructions  on  editing  program
       specified  font patterns before attempting to match the available fonts. It is in xml for-

       conf.d is the conventional name for a directory of additional configuration files  managed
       by  external  applications or the local administrator. The filenames starting with decimal
       digits are sorted in lexicographic order and used as additional configuration  files.  All
       of  these files are in xml format. The master fonts.conf file references this directory in
       an <include> directive.

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

       ~/.fonts.conf.d is the conventional name for a per-user directory of (typically	auto-gen-
       erated)	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.

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

       Fontconfig version 2.8.0

					 18 November 2009			    FONTS-CONF(5)
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