# phpman > man > GROFF_FONT(5) [GROFF_FONT(5)](https://www.chedong.com/phpMan.php/man/GROFFFONT/5/markdown) File Formats Manual [GROFF_FONT(5)](https://www.chedong.com/phpMan.php/man/GROFFFONT/5/markdown) ## NAME groff_font - format of groff device and font description files ## DESCRIPTION The groff font format is roughly a superset of the ditroff font format. The font files for device _name_ are stored in a directory _dev_name. There are two types of file: a device de‐ scription file called _DESC_ and for each font _F_, a font file called F. These are text files; unlike the ditroff font format, there is no associated binary format. ### DESC file format The _DESC_ file can contain the following types of line as shown below. Later entries in the file override previous values. Empty lines are ignored. ### charset This line and everything following in the file are ignored. It is allowed for the sake of backwards compatibility. **family** _fam_ The default font family is _fam_. **fonts** _n_ _F1_ _F2_ _F3_ _..._ _Fn_ Fonts _F1_, ..., _Fn_ are mounted in the font positions _m_+1, ..., _m_+_n_ where _m_ is the num‐ ber of styles. This command may extend over more than one line. A font name of **0** causes no font to be mounted on the corresponding font position. **hor** _n_ The horizontal resolution is _n_ machine units. **image**___**generator** _string_ Needed for **grohtml** only. It specifies the program to generate PNG images from Post‐ Script input. Under GNU/Linux this is usually _gs_ but under other systems (notably cygwin) it might be set to another name. **paperlength** _n_ The physical vertical dimension of the output medium in machine units. This isn't used by **troff** itself but by output devices. Deprecated. Use **papersize** instead. **papersize** _string_ Select a paper size. Valid values for _string_ are the ISO paper types A0–A7, B0–B7, C0–C7, D0–D7, DL, and the US paper types letter, legal, tabloid, ledger, statement, executive, com10, and monarch. Case is not significant for _string_ if it holds prede‐ fined paper types. Alternatively, _string_ can be a file name (e.g. _/etc/papersize_); if the file can be opened, **groff** reads the first line and tests for the above paper sizes. Finally, _string_ can be a custom paper size in the format _length_**,**_width_ (no spa‐ ces before and after the comma). Both _length_ and _width_ must have a unit appended; valid values are ‘i’ for inches, ‘c’ for centimeters, ‘p’ for points, and ‘P’ for pi‐ cas. Example: **12c,235p**. An argument which starts with a digit is always treated as a custom paper format. **papersize** sets both the vertical and horizontal dimension of the output medium. More than one argument can be specified; **groff** scans from left to right and uses the first valid paper specification. **paperwidth** _n_ The physical horizontal dimension of the output medium in machine units. Deprecated. Use **papersize** instead. This isn't used by **troff** itself but by output devices. **pass**___**filenames** Make troff tell the driver the source file name being processed. This is achieved by another tcommand: **F** _filename_. **postpro** _program_ Use _program_ as the postprocessor. **prepro** _program_ Call _program_ as a preprocessor. **print** _program_ Use _program_ as the spooler program for printing. If omitted, the **-l** and **-L** options of **groff** are ignored. **res** _n_ There are _n_ machine units per inch. **sizes** _s1_ _s2_ _..._ _sn_ **0** This means that the device has fonts at _s1_, _s2_, ..., _sn_ scaled points. The list of sizes must be terminated by a **0**. Each _si_ can also be a range of sizes _m_–_n_. The list can extend over more than one line. **sizescale** _n_ The scale factor for point sizes. By default this has a value of 1. One _scaled_ _point_ is equal to one point/_n_. The arguments to the **unitwidth** and **sizes** commands are given in scaled points. **styles** _S1_ _S2_ _..._ _Sm_ The first _m_ font positions are associated with styles _S1_, ..., _Sm_. ### tcommand This means that the postprocessor can handle the **t** and **u** output commands. ### unicode Indicate that the output device supports the complete Unicode repertoire. Useful only for devices which produce _character_ _entities_ instead of glyphs. If **unicode** is present, no **charset** section is required in the font description files since the Unicode handling built into **groff** is used. However, if there are entries in a **charset** section, they either override the default mappings for those particular characters or add new mappings (normally for composite characters). This is used for **-Tutf8**, **-Thtml**, and **-Txhtml**. **unitwidth** _n_ Quantities in the font files are given in machine units for fonts whose point size is _n_ scaled points. **unscaled**___**charwidths** Make the font handling module always return unscaled glyph widths. Needed for the **grohtml** device. **use**___**charnames**___**in**___**special** This command indicates that troff should encode named glyphs inside special commands. **vert** _n_ The vertical resolution is _n_ machine units. The **res**, **unitwidth**, **fonts**, and **sizes** lines are compulsory. Not all commands in the _DESC_ file are used by **troff** itself; some of the keywords (or even additional ones) are used by postpro‐ cessors to store arbitrary information about the device. Here a list of obsolete keywords which are recognized by **groff** but completely ignored: **spare1**, **spare2**, **biggestfont**. ### Font file format A font file has two sections; empty lines are ignored in both of them. The first section is a sequence of lines each containing a sequence of blank delimited words; the first word in the line is a key, and subsequent words give a value for that key. **ligatures** _lig1_ _lig2_ _..._ _lign_ [**0**] Glyphs _lig1_, _lig2_, ..., _lign_ are ligatures; possible ligatures are **ff**, **fi**, **fl**, **ffi**, and **ffl**. For backwards compatibility, the list of ligatures may be terminated with a **0**. The list of ligatures may not extend over more than one line. **name** _F_ The name of the font is _F_. **slant** _n_ The glyphs of the font have a slant of _n_ degrees. (Positive means forward.) **spacewidth** _n_ The normal width of a space is _n_. ### special The font is _special_; this means that when a glyph is requested that is not present in the current font, it is searched for in any special fonts that are mounted. Other commands are ignored by **troff** but may be used by postprocessors to store arbitrary in‐ formation about the font in the font file. The first section can contain comments which start with the **#** character and extend to the end of a line. The second section contains one or two subsections. It must contain a _charset_ subsection and it may also contain a _kernpairs_ subsection. These subsections can appear in any order. Each subsection starts with a word on a line by itself. The word **charset** starts the charset subsection. The **charset** line is followed by a sequence of lines. Each line gives information for one glyph. A line comprises a number of fields separated by blanks or tabs. The format is _name_ _metrics_ _type_ _code_ [_entity_name_] [**--** _comment_] _name_ identifies the glyph: if _name_ is a single glyph _c_ then it corresponds to the groff input character _c_; if it is of the form **\**_c_ where c is a single character, then it corresponds to the special character **\[**_c_**]**; otherwise it corresponds to the groff input character **\[**_name_**]**. If it is exactly two characters _xx_ it can be entered as **\(**_xx_. Note that single-letter spe‐ cial characters can't be accessed as **\**_c_; the only exception is ‘\-’ which is identical to ‘\[-]’. The name **---** is special and indicates that the glyph is unnamed; such glyphs can only be used by means of the **\N** escape sequence in **troff**. The _type_ field gives the glyph type: 1 means the glyph has a descender, for example, ‘p’; 2 means the glyph has an ascender, for example, ‘b’; 3 means the glyph has both an ascender and a descender, for example, ‘(’. The _code_ field gives the code which the postprocessor uses to print the glyph. The glyph can also be input to groff using this code by means of the **\N** escape sequence. The code can be any integer. If it starts with a **0** it is interpreted as octal; if it starts with **0x** or **0X** it is interpreted as hexadecimal. Note, however, that the **\N** escape sequence only accepts a decimal integer. The _entity_name_ field gives an ASCII string identifying the glyph which the postprocessor uses to print that glyph. This field is optional and is currently used by **grops** to build sub-encoding arrays for PS fonts containing more than 256 glyphs. (It has also been used for **grohtml**'s entity names but for efficiency reasons this data is now compiled directly into **grohtml**.) Anything on the line after the encoding field or ‘--’ are ignored. The _metrics_ field has the form (in one line; it is broken here for the sake of readability): _width_[**,**_height_[**,**_depth_[**,**_italic-correction_ [**,**_left-italic-correction_[**,**_subscript-correction_]]]]] There must not be any spaces between these subfields. Missing subfields are assumed to be 0. The subfields are all decimal integers. Since there is no associated binary format, these values are not required to fit into a variable of type **char** as they are in ditroff. The _width_ subfields gives the width of the glyph. The _height_ subfield gives the height of the glyph (upwards is positive); if a glyph does not extend above the baseline, it should be given a zero height, rather than a negative height. The _depth_ subfield gives the depth of the glyph, that is, the distance below the baseline to which the glyph extends (downwards is positive); if a glyph does not extend below the baseline, it should be given a zero depth, rather than a negative depth. The _italic-correction_ subfield gives the amount of space that should be added after the glyph when it is immediately to be followed by a glyph from a roman font. The _left-italic-correction_ subfield gives the amount of space that should be added be‐ fore the glyph when it is immediately to be preceded by a glyph from a roman font. The _sub__‐ _script-correction_ gives the amount of space that should be added after a glyph before adding a subscript. This should be less than the italic correction. A line in the charset section can also have the format _name_ **"** This indicates that _name_ is just another name for the glyph mentioned in the preceding line. The word **kernpairs** starts the kernpairs section. This contains a sequence of lines of the form: _c1_ _c2_ _n_ This means that when glyph _c1_ appears next to glyph _c2_ the space between them should be in‐ creased by _n_. Most entries in kernpairs section have a negative value for _n_. ## FILES _/usr/share/groff/1.22.4/font/dev_name_/DESC_ Device description file for device _name_. _/usr/share/groff/1.22.4/font/dev_name_/_F Font file for font _F_ of device _name_. ## SEE ALSO **groff**___**[out**(5)](https://www.chedong.com/phpMan.php/man/out/5/markdown), [**troff**(1)](https://www.chedong.com/phpMan.php/man/troff/1/markdown), [**addftinfo**(1)](https://www.chedong.com/phpMan.php/man/addftinfo/1/markdown), [**afmtodit**(1)](https://www.chedong.com/phpMan.php/man/afmtodit/1/markdown) A man page [_name_(_n_)](https://www.chedong.com/phpMan.php/man/name/n/markdown) of section _n_ can be viewed either with $ **man** _n_ _name_ for text mode or $ **groffer** _n_ _name_ for graphical mode (default is PDF mode). groff 1.22.4 23 March 2022 [GROFF_FONT(5)](https://www.chedong.com/phpMan.php/man/GROFFFONT/5/markdown)