fontconfig-user.txt revision a32e9e42
1 fonts-conf 2 3Name 4 5 fonts.conf -- Font configuration files 6 7Synopsis 8 9 /etc/fonts/fonts.conf 10 /etc/fonts/fonts.dtd 11 /etc/fonts/conf.d 12 $XDG_CONFIG_HOME/fontconfig/conf.d 13 $XDG_CONFIG_HOME/fontconfig/fonts.conf 14 ~/.fonts.conf.d 15 ~/.fonts.conf 16 17Description 18 19 Fontconfig is a library designed to provide system-wide font 20 configuration, customization and application access. 21 22Functional Overview 23 24 Fontconfig contains two essential modules, the configuration module which 25 builds an internal configuration from XML files and the matching module 26 which accepts font patterns and returns the nearest matching font. 27 28 Font Configuration 29 30 The configuration module consists of the FcConfig datatype, libexpat and 31 FcConfigParse which walks over an XML tree and amends a configuration with 32 data found within. From an external perspective, configuration of the 33 library consists of generating a valid XML tree and feeding that to 34 FcConfigParse. The only other mechanism provided to applications for 35 changing the running configuration is to add fonts and directories to the 36 list of application-provided font files. 37 38 The intent is to make font configurations relatively static, and shared by 39 as many applications as possible. It is hoped that this will lead to more 40 stable font selection when passing names from one application to another. 41 XML was chosen as a configuration file format because it provides a format 42 which is easy for external agents to edit while retaining the correct 43 structure and syntax. 44 45 Font configuration is separate from font matching; applications needing to 46 do their own matching can access the available fonts from the library and 47 perform private matching. The intent is to permit applications to pick and 48 choose appropriate functionality from the library instead of forcing them 49 to choose between this library and a private configuration mechanism. The 50 hope is that this will ensure that configuration of fonts for all 51 applications can be centralized in one place. Centralizing font 52 configuration will simplify and regularize font installation and 53 customization. 54 55 Font Properties 56 57 While font patterns may contain essentially any properties, there are some 58 well known properties with associated types. Fontconfig uses some of these 59 properties for font matching and font completion. Others are provided as a 60 convenience for the applications' rendering mechanism. 61 62 Property Type Description 63 -------------------------------------------------------------- 64 family String Font family names 65 familylang String Languages corresponding to each family 66 style String Font style. Overrides weight and slant 67 stylelang String Languages corresponding to each style 68 fullname String Font full names (often includes style) 69 fullnamelang String Languages corresponding to each fullname 70 slant Int Italic, oblique or roman 71 weight Int Light, medium, demibold, bold or black 72 size Double Point size 73 width Int Condensed, normal or expanded 74 aspect Double Stretches glyphs horizontally before hinting 75 pixelsize Double Pixel size 76 spacing Int Proportional, dual-width, monospace or charcell 77 foundry String Font foundry name 78 antialias Bool Whether glyphs can be antialiased 79 hinting Bool Whether the rasterizer should use hinting 80 hintstyle Int Automatic hinting style 81 verticallayout Bool Use vertical layout 82 autohint Bool Use autohinter instead of normal hinter 83 globaladvance Bool Use font global advance data (deprecated) 84 file String The filename holding the font 85 index Int The index of the font within the file 86 ftface FT_Face Use the specified FreeType face object 87 rasterizer String Which rasterizer is in use (deprecated) 88 outline Bool Whether the glyphs are outlines 89 scalable Bool Whether glyphs can be scaled 90 color Bool Whether any glyphs have color 91 scale Double Scale factor for point->pixel conversions (deprecated) 92 dpi Double Target dots per inch 93 rgba Int unknown, rgb, bgr, vrgb, vbgr, 94 none - subpixel geometry 95 lcdfilter Int Type of LCD filter 96 minspace Bool Eliminate leading from line spacing 97 charset CharSet Unicode chars encoded by the font 98 lang String List of RFC-3066-style languages this 99 font supports 100 fontversion Int Version number of the font 101 capability String List of layout capabilities in the font 102 fontformat String String name of the font format 103 embolden Bool Rasterizer should synthetically embolden the font 104 embeddedbitmap Bool Use the embedded bitmap instead of the outline 105 decorative Bool Whether the style is a decorative variant 106 fontfeatures String List of the feature tags in OpenType to be enabled 107 namelang String Language name to be used for the default value of 108 familylang, stylelang, and fullnamelang 109 prgname String String Name of the running program 110 postscriptname String Font family name in PostScript 111 112 113 Font Matching 114 115 Fontconfig performs matching by measuring the distance from a provided 116 pattern to all of the available fonts in the system. The closest matching 117 font is selected. This ensures that a font will always be returned, but 118 doesn't ensure that it is anything like the requested pattern. 119 120 Font matching starts with an application constructed pattern. The desired 121 attributes of the resulting font are collected together in a pattern. Each 122 property of the pattern can contain one or more values; these are listed 123 in priority order; matches earlier in the list are considered "closer" 124 than matches later in the list. 125 126 The initial pattern is modified by applying the list of editing 127 instructions specific to patterns found in the configuration; each 128 consists of a match predicate and a set of editing operations. They are 129 executed in the order they appeared in the configuration. Each match 130 causes the associated sequence of editing operations to be applied. 131 132 After the pattern has been edited, a sequence of default substitutions are 133 performed to canonicalize the set of available properties; this avoids the 134 need for the lower layers to constantly provide default values for various 135 font properties during rendering. 136 137 The canonical font pattern is finally matched against all available fonts. 138 The distance from the pattern to the font is measured for each of several 139 properties: foundry, charset, family, lang, spacing, pixelsize, style, 140 slant, weight, antialias, rasterizer and outline. This list is in priority 141 order -- results of comparing earlier elements of this list weigh more 142 heavily than later elements. 143 144 There is one special case to this rule; family names are split into two 145 bindings; strong and weak. Strong family names are given greater 146 precedence in the match than lang elements while weak family names are 147 given lower precedence than lang elements. This permits the document 148 language to drive font selection when any document specified font is 149 unavailable. 150 151 The pattern representing that font is augmented to include any properties 152 found in the pattern but not found in the font itself; this permits the 153 application to pass rendering instructions or any other data through the 154 matching system. Finally, the list of editing instructions specific to 155 fonts found in the configuration are applied to the pattern. This modified 156 pattern is returned to the application. 157 158 The return value contains sufficient information to locate and rasterize 159 the font, including the file name, pixel size and other rendering data. As 160 none of the information involved pertains to the FreeType library, 161 applications are free to use any rasterization engine or even to take the 162 identified font file and access it directly. 163 164 The match/edit sequences in the configuration are performed in two passes 165 because there are essentially two different operations necessary -- the 166 first is to modify how fonts are selected; aliasing families and adding 167 suitable defaults. The second is to modify how the selected fonts are 168 rasterized. Those must apply to the selected font, not the original 169 pattern as false matches will often occur. 170 171 Font Names 172 173 Fontconfig provides a textual representation for patterns that the library 174 can both accept and generate. The representation is in three parts, first 175 a list of family names, second a list of point sizes and finally a list of 176 additional properties: 177 178 <families>-<point sizes>:<name1>=<values1>:<name2>=<values2>... 179 180 181 Values in a list are separated with commas. The name needn't include 182 either families or point sizes; they can be elided. In addition, there are 183 symbolic constants that simultaneously indicate both a name and a value. 184 Here are some examples: 185 186 Name Meaning 187 ---------------------------------------------------------- 188 Times-12 12 point Times Roman 189 Times-12:bold 12 point Times Bold 190 Courier:italic Courier Italic in the default size 191 Monospace:matrix=1 .1 0 1 The users preferred monospace font 192 with artificial obliquing 193 194 195 The '\', '-', ':' and ',' characters in family names must be preceded by a 196 '\' character to avoid having them misinterpreted. Similarly, values 197 containing '\', '=', '_', ':' and ',' must also have them preceded by a 198 '\' character. The '\' characters are stripped out of the family name and 199 values as the font name is read. 200 201Debugging Applications 202 203 To help diagnose font and applications problems, fontconfig is built with 204 a large amount of internal debugging left enabled. It is controlled by 205 means of the FC_DEBUG environment variable. The value of this variable is 206 interpreted as a number, and each bit within that value controls different 207 debugging messages. 208 209 Name Value Meaning 210 --------------------------------------------------------- 211 MATCH 1 Brief information about font matching 212 MATCHV 2 Extensive font matching information 213 EDIT 4 Monitor match/test/edit execution 214 FONTSET 8 Track loading of font information at startup 215 CACHE 16 Watch cache files being written 216 CACHEV 32 Extensive cache file writing information 217 PARSE 64 (no longer in use) 218 SCAN 128 Watch font files being scanned to build caches 219 SCANV 256 Verbose font file scanning information 220 MEMORY 512 Monitor fontconfig memory usage 221 CONFIG 1024 Monitor which config files are loaded 222 LANGSET 2048 Dump char sets used to construct lang values 223 MATCH2 4096 Display font-matching transformation in patterns 224 225 226 Add the value of the desired debug levels together and assign that (in 227 base 10) to the FC_DEBUG environment variable before running the 228 application. Output from these statements is sent to stdout. 229 230Lang Tags 231 232 Each font in the database contains a list of languages it supports. This 233 is computed by comparing the Unicode coverage of the font with the 234 orthography of each language. Languages are tagged using an RFC-3066 235 compatible naming and occur in two parts -- the ISO 639 language tag 236 followed a hyphen and then by the ISO 3166 country code. The hyphen and 237 country code may be elided. 238 239 Fontconfig has orthographies for several languages built into the library. 240 No provision has been made for adding new ones aside from rebuilding the 241 library. It currently supports 122 of the 139 languages named in ISO 242 639-1, 141 of the languages with two-letter codes from ISO 639-2 and 243 another 30 languages with only three-letter codes. Languages with both two 244 and three letter codes are provided with only the two letter code. 245 246 For languages used in multiple territories with radically different 247 character sets, fontconfig includes per-territory orthographies. This 248 includes Azerbaijani, Kurdish, Pashto, Tigrinya and Chinese. 249 250Configuration File Format 251 252 Configuration files for fontconfig are stored in XML format; this format 253 makes external configuration tools easier to write and ensures that they 254 will generate syntactically correct configuration files. As XML files are 255 plain text, they can also be manipulated by the expert user using a text 256 editor. 257 258 The fontconfig document type definition resides in the external entity 259 "fonts.dtd"; this is normally stored in the default font configuration 260 directory (/etc/fonts). Each configuration file should contain the 261 following structure: 262 263 <?xml version="1.0"?> 264 <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> 265 <fontconfig> 266 ... 267 </fontconfig> 268 269 270 <fontconfig> 271 272 This is the top level element for a font configuration and can contain 273 <dir>, <cachedir>, <include>, <match> and <alias> elements in any order. 274 275 <dir prefix="default"> 276 277 This element contains a directory name which will be scanned for font 278 files to include in the set of available fonts. If 'prefix' is set to 279 "xdg", the value in the XDG_DATA_HOME environment variable will be added 280 as the path prefix. please see XDG Base Directory Specification for more 281 details. 282 283 <cachedir prefix="default"> 284 285 This element contains a directory name that is supposed to be stored or 286 read the cache of font information. If multiple elements are specified in 287 the configuration file, the directory that can be accessed first in the 288 list will be used to store the cache files. If it starts with '~', it 289 refers to a directory in the users home directory. If 'prefix' is set to 290 "xdg", the value in the XDG_CACHE_HOME environment variable will be added 291 as the path prefix. please see XDG Base Directory Specification for more 292 details. The default directory is ``$XDG_CACHE_HOME/fontconfig'' and it 293 contains the cache files named ``<hash 294 value>-<architecture>.cache-<version>'', where <version> is the fontconfig 295 cache file version number (currently 7). 296 297 <include ignore_missing="no" prefix="default"> 298 299 This element contains the name of an additional configuration file or 300 directory. If a directory, every file within that directory starting with 301 an ASCII digit (U+0030 - U+0039) and ending with the string ``.conf'' will 302 be processed in sorted order. When the XML datatype is traversed by 303 FcConfigParse, the contents of the file(s) will also be incorporated into 304 the configuration by passing the filename(s) to FcConfigLoadAndParse. If 305 'ignore_missing' is set to "yes" instead of the default "no", a missing 306 file or directory will elicit no warning message from the library. If 307 'prefix' is set to "xdg", the value in the XDG_CONFIG_HOME environment 308 variable will be added as the path prefix. please see XDG Base Directory 309 Specification for more details. 310 311 <config> 312 313 This element provides a place to consolidate additional configuration 314 information. <config> can contain <blank> and <rescan> elements in any 315 order. 316 317 <blank> 318 319 Fonts often include "broken" glyphs which appear in the encoding but are 320 drawn as blanks on the screen. Within the <blank> element, place each 321 Unicode characters which is supposed to be blank in an <int> element. 322 Characters outside of this set which are drawn as blank will be elided 323 from the set of characters supported by the font. 324 325 <rescan> 326 327 The <rescan> element holds an <int> element which indicates the default 328 interval between automatic checks for font configuration changes. 329 Fontconfig will validate all of the configuration files and directories 330 and automatically rebuild the internal datastructures when this interval 331 passes. 332 333 <selectfont> 334 335 This element is used to black/white list fonts from being listed or 336 matched against. It holds acceptfont and rejectfont elements. 337 338 <acceptfont> 339 340 Fonts matched by an acceptfont element are "whitelisted"; such fonts are 341 explicitly included in the set of fonts used to resolve list and match 342 requests; including them in this list protects them from being 343 "blacklisted" by a rejectfont element. Acceptfont elements include glob 344 and pattern elements which are used to match fonts. 345 346 <rejectfont> 347 348 Fonts matched by an rejectfont element are "blacklisted"; such fonts are 349 excluded from the set of fonts used to resolve list and match requests as 350 if they didn't exist in the system. Rejectfont elements include glob and 351 pattern elements which are used to match fonts. 352 353 <glob> 354 355 Glob elements hold shell-style filename matching patterns (including ? and 356 *) which match fonts based on their complete pathnames. This can be used 357 to exclude a set of directories (/usr/share/fonts/uglyfont*), or 358 particular font file types (*.pcf.gz), but the latter mechanism relies 359 rather heavily on filenaming conventions which can't be relied upon. Note 360 that globs only apply to directories, not to individual fonts. 361 362 <pattern> 363 364 Pattern elements perform list-style matching on incoming fonts; that is, 365 they hold a list of elements and associated values. If all of those 366 elements have a matching value, then the pattern matches the font. This 367 can be used to select fonts based on attributes of the font (scalable, 368 bold, etc), which is a more reliable mechanism than using file extensions. 369 Pattern elements include patelt elements. 370 371 <patelt name="property"> 372 373 Patelt elements hold a single pattern element and list of values. They 374 must have a 'name' attribute which indicates the pattern element name. 375 Patelt elements include int, double, string, matrix, bool, charset and 376 const elements. 377 378 <match target="pattern"> 379 380 This element holds first a (possibly empty) list of <test> elements and 381 then a (possibly empty) list of <edit> elements. Patterns which match all 382 of the tests are subjected to all the edits. If 'target' is set to "font" 383 instead of the default "pattern", then this element applies to the font 384 name resulting from a match rather than a font pattern to be matched. If 385 'target' is set to "scan", then this element applies when the font is 386 scanned to build the fontconfig database. 387 388 <test qual="any" name="property" target="default" compare="eq"> 389 390 This element contains a single value which is compared with the target 391 ('pattern', 'font', 'scan' or 'default') property "property" (substitute 392 any of the property names seen above). 'compare' can be one of "eq", 393 "not_eq", "less", "less_eq", "more", "more_eq", "contains" or 394 "not_contains". 'qual' may either be the default, "any", in which case the 395 match succeeds if any value associated with the property matches the test 396 value, or "all", in which case all of the values associated with the 397 property must match the test value. 'ignore-blanks' takes a boolean value. 398 if 'ignore-blanks' is set "true", any blanks in the string will be ignored 399 on its comparison. this takes effects only when compare="eq" or 400 compare="not_eq". When used in a <match target="font"> element, the 401 target= attribute in the <test> element selects between matching the 402 original pattern or the font. "default" selects whichever target the outer 403 <match> element has selected. 404 405 <edit name="property" mode="assign" binding="weak"> 406 407 This element contains a list of expression elements (any of the value or 408 operator elements). The expression elements are evaluated at run-time and 409 modify the property "property". The modification depends on whether 410 "property" was matched by one of the associated <test> elements, if so, 411 the modification may affect the first matched value. Any values inserted 412 into the property are given the indicated binding ("strong", "weak" or 413 "same") with "same" binding using the value from the matched pattern 414 element. 'mode' is one of: 415 416 Mode With Match Without Match 417 --------------------------------------------------------------------- 418 "assign" Replace matching value Replace all values 419 "assign_replace" Replace all values Replace all values 420 "prepend" Insert before matching Insert at head of list 421 "prepend_first" Insert at head of list Insert at head of list 422 "append" Append after matching Append at end of list 423 "append_last" Append at end of list Append at end of list 424 "delete" Delete matching value Delete all values 425 "delete_all" Delete all values Delete all values 426 427 428 <int>, <double>, <string>, <bool> 429 430 These elements hold a single value of the indicated type. <bool> elements 431 hold either true or false. An important limitation exists in the parsing 432 of floating point numbers -- fontconfig requires that the mantissa start 433 with a digit, not a decimal point, so insert a leading zero for purely 434 fractional values (e.g. use 0.5 instead of .5 and -0.5 instead of -.5). 435 436 <matrix> 437 438 This element holds four numerical expressions of an affine transformation. 439 At their simplest these will be four <double> elements but they can also 440 be more involved expressions. 441 442 <range> 443 444 This element holds the two <int> elements of a range representation. 445 446 <charset> 447 448 This element holds at least one <int> element of an Unicode code point or 449 more. 450 451 <langset> 452 453 This element holds at least one <string> element of a RFC-3066-style 454 languages or more. 455 456 <name> 457 458 Holds a property name. Evaluates to the first value from the property of 459 the pattern. If the 'target' attribute is not present, it will default to 460 'default', in which case the property is returned from the font pattern 461 during a target="font" match, and to the pattern during a target="pattern" 462 match. The attribute can also take the values 'font' or 'pattern' to 463 explicitly choose which pattern to use. It is an error to use a target of 464 'font' in a match that has target="pattern". 465 466 <const> 467 468 Holds the name of a constant; these are always integers and serve as 469 symbolic names for common font values: 470 471 Constant Property Value 472 ------------------------------------- 473 thin weight 0 474 extralight weight 40 475 ultralight weight 40 476 light weight 50 477 demilight weight 55 478 semilight weight 55 479 book weight 75 480 regular weight 80 481 normal weight 80 482 medium weight 100 483 demibold weight 180 484 semibold weight 180 485 bold weight 200 486 extrabold weight 205 487 black weight 210 488 heavy weight 210 489 roman slant 0 490 italic slant 100 491 oblique slant 110 492 ultracondensed width 50 493 extracondensed width 63 494 condensed width 75 495 semicondensed width 87 496 normal width 100 497 semiexpanded width 113 498 expanded width 125 499 extraexpanded width 150 500 ultraexpanded width 200 501 proportional spacing 0 502 dual spacing 90 503 mono spacing 100 504 charcell spacing 110 505 unknown rgba 0 506 rgb rgba 1 507 bgr rgba 2 508 vrgb rgba 3 509 vbgr rgba 4 510 none rgba 5 511 lcdnone lcdfilter 0 512 lcddefault lcdfilter 1 513 lcdlight lcdfilter 2 514 lcdlegacy lcdfilter 3 515 hintnone hintstyle 0 516 hintslight hintstyle 1 517 hintmedium hintstyle 2 518 hintfull hintstyle 3 519 520 521 <or>, <and>, <plus>, <minus>, <times>, <divide> 522 523 These elements perform the specified operation on a list of expression 524 elements. <or> and <and> are boolean, not bitwise. 525 526 <eq>, <not_eq>, <less>, <less_eq>, <more>, <more_eq>, <contains>, 527 <not_contains 528 529 These elements compare two values, producing a boolean result. 530 531 <not> 532 533 Inverts the boolean sense of its one expression element 534 535 <if> 536 537 This element takes three expression elements; if the value of the first is 538 true, it produces the value of the second, otherwise it produces the value 539 of the third. 540 541 <alias> 542 543 Alias elements provide a shorthand notation for the set of common match 544 operations needed to substitute one font family for another. They contain 545 a <family> element followed by optional <prefer>, <accept> and <default> 546 elements. Fonts matching the <family> element are edited to prepend the 547 list of <prefer>ed families before the matching <family>, append the 548 <accept>able families after the matching <family> and append the <default> 549 families to the end of the family list. 550 551 <family> 552 553 Holds a single font family name 554 555 <prefer>, <accept>, <default> 556 557 These hold a list of <family> elements to be used by the <alias> element. 558 559EXAMPLE CONFIGURATION FILE 560 561 System configuration file 562 563 This is an example of a system-wide configuration file 564 565<?xml version="1.0"?> 566<!DOCTYPE fontconfig SYSTEM "fonts.dtd"> 567<!-- /etc/fonts/fonts.conf file to configure system font access --> 568<fontconfig> 569<!-- 570 Find fonts in these directories 571--> 572<dir>/usr/share/fonts</dir> 573<dir>/usr/X11R6/lib/X11/fonts</dir> 574 575<!-- 576 Accept deprecated 'mono' alias, replacing it with 'monospace' 577--> 578<match target="pattern"> 579 <test qual="any" name="family"><string>mono</string></test> 580 <edit name="family" mode="assign"><string>monospace</string></edit> 581</match> 582 583<!-- 584 Names not including any well known alias are given 'sans-serif' 585--> 586<match target="pattern"> 587 <test qual="all" name="family" compare="not_eq"><string>sans-serif</string></test> 588 <test qual="all" name="family" compare="not_eq"><string>serif</string></test> 589 <test qual="all" name="family" compare="not_eq"><string>monospace</string></test> 590 <edit name="family" mode="append_last"><string>sans-serif</string></edit> 591</match> 592 593<!-- 594 Load per-user customization file, but don't complain 595 if it doesn't exist 596--> 597<include ignore_missing="yes" prefix="xdg">fontconfig/fonts.conf</include> 598 599<!-- 600 Load local customization files, but don't complain 601 if there aren't any 602--> 603<include ignore_missing="yes">conf.d</include> 604<include ignore_missing="yes">local.conf</include> 605 606<!-- 607 Alias well known font names to available TrueType fonts. 608 These substitute TrueType faces for similar Type1 609 faces to improve screen appearance. 610--> 611<alias> 612 <family>Times</family> 613 <prefer><family>Times New Roman</family></prefer> 614 <default><family>serif</family></default> 615</alias> 616<alias> 617 <family>Helvetica</family> 618 <prefer><family>Arial</family></prefer> 619 <default><family>sans</family></default> 620</alias> 621<alias> 622 <family>Courier</family> 623 <prefer><family>Courier New</family></prefer> 624 <default><family>monospace</family></default> 625</alias> 626 627<!-- 628 Provide required aliases for standard names 629 Do these after the users configuration file so that 630 any aliases there are used preferentially 631--> 632<alias> 633 <family>serif</family> 634 <prefer><family>Times New Roman</family></prefer> 635</alias> 636<alias> 637 <family>sans</family> 638 <prefer><family>Arial</family></prefer> 639</alias> 640<alias> 641 <family>monospace</family> 642 <prefer><family>Andale Mono</family></prefer> 643</alias> 644 645<-- 646 The example of the requirements of OR operator; 647 If the 'family' contains 'Courier New' OR 'Courier' 648 add 'monospace' as the alternative 649--> 650<match target="pattern"> 651 <test name="family" compare="eq"> 652 <string>Courier New</string> 653 </test> 654 <edit name="family" mode="prepend"> 655 <string>monospace</string> 656 </edit> 657</match> 658<match target="pattern"> 659 <test name="family" compare="eq"> 660 <string>Courier</string> 661 </test> 662 <edit name="family" mode="prepend"> 663 <string>monospace</string> 664 </edit> 665</match> 666 667</fontconfig> 668 669 670 User configuration file 671 672 This is an example of a per-user configuration file that lives in 673 $XDG_CONFIG_HOME/fontconfig/fonts.conf 674 675 <?xml version="1.0"?> 676 <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> 677 <!-- $XDG_CONFIG_HOME/fontconfig/fonts.conf for per-user font configuration --> 678 <fontconfig> 679 680 <!-- 681 Private font directory 682 --> 683 <dir prefix="xdg">fonts</dir> 684 685 <!-- 686 use rgb sub-pixel ordering to improve glyph appearance on 687 LCD screens. Changes affecting rendering, but not matching 688 should always use target="font". 689 --> 690 <match target="font"> 691 <edit name="rgba" mode="assign"><const>rgb</const></edit> 692 </match> 693 <!-- 694 use WenQuanYi Zen Hei font when serif is requested for Chinese 695 --> 696 <match> 697 <!-- 698 If you don't want to use WenQuanYi Zen Hei font for zh-tw etc, 699 you can use zh-cn instead of zh. 700 Please note, even if you set zh-cn, it still matches zh. 701 if you don't like it, you can use compare="eq" 702 instead of compare="contains". 703 --> 704 <test name="lang" compare="contains"> 705 <string>zh</string> 706 </test> 707 <test name="family"> 708 <string>serif</string> 709 </test> 710 <edit name="family" mode="prepend"> 711 <string>WenQuanYi Zen Hei</string> 712 </edit> 713 </match> 714 <!-- 715 use VL Gothic font when sans-serif is requested for Japanese 716 --> 717 <match> 718 <test name="lang" compare="contains"> 719 <string>ja</string> 720 </test> 721 <test name="family"> 722 <string>sans-serif</string> 723 </test> 724 <edit name="family" mode="prepend"> 725 <string>VL Gothic</string> 726 </edit> 727 </match> 728 </fontconfig> 729 730 731Files 732 733 fonts.conf contains configuration information for the fontconfig library 734 consisting of directories to look at for font information as well as 735 instructions on editing program specified font patterns before attempting 736 to match the available fonts. It is in XML format. 737 738 conf.d is the conventional name for a directory of additional 739 configuration files managed by external applications or the local 740 administrator. The filenames starting with decimal digits are sorted in 741 lexicographic order and used as additional configuration files. All of 742 these files are in XML format. The master fonts.conf file references this 743 directory in an <include> directive. 744 745 fonts.dtd is a DTD that describes the format of the configuration files. 746 747 $XDG_CONFIG_HOME/fontconfig/conf.d and ~/.fonts.conf.d is the conventional 748 name for a per-user directory of (typically auto-generated) configuration 749 files, although the actual location is specified in the global fonts.conf 750 file. please note that ~/.fonts.conf.d is deprecated now. it will not be 751 read by default in the future version. 752 753 $XDG_CONFIG_HOME/fontconfig/fonts.conf and ~/.fonts.conf is the 754 conventional location for per-user font configuration, although the actual 755 location is specified in the global fonts.conf file. please note that 756 ~/.fonts.conf is deprecated now. it will not be read by default in the 757 future version. 758 759 $XDG_CACHE_HOME/fontconfig/*.cache-* and ~/.fontconfig/*.cache-* is the 760 conventional repository of font information that isn't found in the 761 per-directory caches. This file is automatically maintained by fontconfig. 762 please note that ~/.fontconfig/*.cache-* is deprecated now. it will not be 763 read by default in the future version. 764 765Environment variables 766 767 FONTCONFIG_FILE is used to override the default configuration file. 768 769 FONTCONFIG_PATH is used to override the default configuration directory. 770 771 FONTCONFIG_SYSROOT is used to set a default sysroot directory. 772 773 FC_DEBUG is used to output the detailed debugging messages. see 774 [1]Debugging Applications section for more details. 775 776 FC_DBG_MATCH_FILTER is used to filter out the patterns. this takes a 777 comma-separated list of object names and effects only when FC_DEBUG has 778 MATCH2. see [2]Debugging Applications section for more details. 779 780 FC_LANG is used to specify the default language as the weak binding in the 781 query. if this isn't set, the default language will be determined from 782 current locale. 783 784 FONTCONFIG_USE_MMAP is used to control the use of mmap(2) for the cache 785 files if available. this take a boolean value. fontconfig will checks if 786 the cache files are stored on the filesystem that is safe to use mmap(2). 787 explicitly setting this environment variable will causes skipping this 788 check and enforce to use or not use mmap(2) anyway. 789 790 SOURCE_DATE_EPOCH is used to ensure fc-cache(1) generates files in a 791 deterministic manner in order to support reproducible builds. When set to 792 a numeric representation of UNIX timestamp, fontconfig will prefer this 793 value over using the modification timestamps of the input files in order 794 to identify which cache files require regeneration. If SOURCE_DATE_EPOCH 795 is not set (or is newer than the mtime of the directory), the existing 796 behaviour is unchanged. 797 798See Also 799 800 fc-cat(1), fc-cache(1), fc-list(1), fc-match(1), fc-query(1), 801 [3]SOURCE_DATE_EPOCH. 802 803Version 804 805 Fontconfig version 2.13.1 806 807References 808 809 Visible links 810 1. file:///tmp/html-cm5uzN#DEBUG 811 2. file:///tmp/html-cm5uzN#DEBUG 812 3. https://reproducible-builds.org/specs/source-date-epoch/ 813