1GROFF_FONT(5) File Formats Manual GROFF_FONT(5)
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6 groff_font - format of groff device and font description files
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9 The groff font format is roughly a superset of the ditroff font format.
10 The font files for device name are stored in a directory devname.
11 There are two types of file: a device description file called DESC and
12 for each font F, a font file called F. These are text files; unlike
13 the ditroff font format, there is no associated binary format.
14 DESC file format
16 The DESC file can contain the following types of line as shown below.
17 Later entries in the file override previous values.
18 Empty lines are ignored.
20 charset
22 This line and everything following in the file are ignored. It
23 is allowed for the sake of backwards compatibility.
24 family fam
26 The default font family is fam.
27 fonts n F1 F2 F3 ... Fn
29 Fonts F1, ..., Fn are mounted in the font positions m+1, ...,
30 m+n where m is the number of styles. This command may extend
31 over more than one line. A font name of 0 causes no font to be
32 mounted on the corresponding font position.
33 hor n The horizontal resolution is n machine units.
35 image_generator string
37 Needed for grohtml only. It specifies the program to generate
38 PNG images from PostScript input. Under GNU/Linux this is usu‐
39 ally gs but under other systems (notably cygwin) it might be set
40 to another name.
41 paperlength n
43 The physical vertical dimension of the output medium in machine
44 units. This isn't used by troff itself but by output devices.
45 Deprecated. Use papersize instead.
46 papersize string
48 Select a paper size. Valid values for string are the ISO paper
49 types A0–A7, B0–B7, C0–C7, D0–D7, DL, and the US paper types
50 letter, legal, tabloid, ledger, statement, executive, com10, and
51 monarch. Case is not significant for string if it holds prede‐
52 fined paper types. Alternatively, string can be a file name
53 (e.g. /etc/papersize); if the file can be opened, groff reads
54 the first line and tests for the above paper sizes. Finally,
55 string can be a custom paper size in the format length,width (no
56 spaces before and after the comma). Both length and width must
57 have a unit appended; valid values are ‘i’ for inches, ‘c’ for
58 centimeters, ‘p’ for points, and ‘P’ for picas. Example:
59 12c,235p. An argument which starts with a digit is always
60 treated as a custom paper format. papersize sets both the ver‐
61 tical and horizontal dimension of the output medium.
62 More than one argument can be specified; groff scans from left
64 to right and uses the first valid paper specification.
65 paperwidth n
67 The physical horizontal dimension of the output medium in ma‐
68 chine units. Deprecated. Use papersize instead. This isn't
69 used by troff itself but by output devices.
70 pass_filenames
72 Make troff tell the driver the source file name being processed.
73 This is achieved by another tcommand: F filename.
74 postpro program
76 Use program as the postprocessor.
77 prepro program
79 Call program as a preprocessor.
80 print program
82 Use program as the spooler program for printing. If omitted,
83 the -l and -L options of groff are ignored.
84 res n There are n machine units per inch.
86 sizes s1 s2 ... sn 0
88 This means that the device has fonts at s1, s2, ..., sn scaled
89 points. The list of sizes must be terminated by a 0. Each si
90 can also be a range of sizes m–n. The list can extend over more
91 than one line.
92 sizescale n
94 The scale factor for point sizes. By default this has a value
95 of 1. One scaled point is equal to one point/n. The arguments
96 to the unitwidth and sizes commands are given in scaled points.
97 styles S1 S2 ... Sm
99 The first m font positions are associated with styles S1, ...,
100 Sm.
101 tcommand
103 This means that the postprocessor can handle the t and u output
104 commands.
105 unicode
107 Indicate that the output device supports the complete Unicode
108 repertoire. Useful only for devices which produce character en‐
109 tities instead of glyphs.
110 If unicode is present, no charset section is required in the
112 font description files since the Unicode handling built into
113 groff is used. However, if there are entries in a charset sec‐
114 tion, they either override the default mappings for those par‐
115 ticular characters or add new mappings (normally for composite
116 characters).
117 This is used for -Tutf8, -Thtml, and -Txhtml.
119 unitwidth n
121 Quantities in the font files are given in machine units for
122 fonts whose point size is n scaled points.
123 unscaled_charwidths
125 Make the font handling module always return unscaled glyph
126 widths. Needed for the grohtml device.
127 use_charnames_in_special
129 This command indicates that troff should encode named glyphs in‐
130 side special commands.
131 vert n The vertical resolution is n machine units.
133 The res, unitwidth, fonts, and sizes lines are compulsory. Not all
135 commands in the DESC file are used by troff itself; some of the key‐
136 words (or even additional ones) are used by postprocessors to store ar‐
137 bitrary information about the device.
138 Here a list of obsolete keywords which are recognized by groff but com‐
140 pletely ignored: spare1, spare2, biggestfont.
141 Font file format
143 A font file has two sections; empty lines are ignored in both of them.
144 The first section is a sequence of lines each containing a sequence of
146 blank delimited words; the first word in the line is a key, and subse‐
147 quent words give a value for that key.
148 ligatures lig1 lig2 ... lign [0]
150 Glyphs lig1, lig2, ..., lign are ligatures; possible ligatures
151 are ff, fi, fl, ffi, and ffl. For backwards compatibility, the
152 list of ligatures may be terminated with a 0. The list of liga‐
153 tures may not extend over more than one line.
154 name F The name of the font is F.
156 slant n
158 The glyphs of the font have a slant of n degrees. (Positive
159 means forward.)
160 spacewidth n
162 The normal width of a space is n.
163 special
165 The font is special; this means that when a glyph is requested
166 that is not present in the current font, it is searched for in
167 any special fonts that are mounted.
168 Other commands are ignored by troff but may be used by postprocessors
170 to store arbitrary information about the font in the font file.
171 The first section can contain comments which start with the # character
173 and extend to the end of a line.
174 The second section contains one or two subsections. It must contain a
176 charset subsection and it may also contain a kernpairs subsection.
177 These subsections can appear in any order. Each subsection starts with
178 a word on a line by itself.
179 The word charset starts the charset subsection. The charset line is
181 followed by a sequence of lines. Each line gives information for one
182 glyph. A line comprises a number of fields separated by blanks or
183 tabs. The format is
184 name metrics type code [entity_name] [-- comment]
186 name identifies the glyph: if name is a single glyph c then it corre‐
188 sponds to the groff input character c; if it is of the form \c where c
189 is a single character, then it corresponds to the special character
190 \[c]; otherwise it corresponds to the groff input character \[name].
191 If it is exactly two characters xx it can be entered as \(xx. Note
192 that single-letter special characters can't be accessed as \c; the only
193 exception is ‘\-’ which is identical to ‘\[-]’. The name --- is spe‐
194 cial and indicates that the glyph is unnamed; such glyphs can only be
195 used by means of the \N escape sequence in troff.
196 The type field gives the glyph type:
198 1 means the glyph has a descender, for example, ‘p’;
200 2 means the glyph has an ascender, for example, ‘b’;
202 3 means the glyph has both an ascender and a descender, for exam‐
204 ple, ‘(’.
205 The code field gives the code which the postprocessor uses to print the
207 glyph. The glyph can also be input to groff using this code by means
208 of the \N escape sequence. The code can be any integer. If it starts
209 with a 0 it is interpreted as octal; if it starts with 0x or 0X it is
210 interpreted as hexadecimal. Note, however, that the \N escape sequence
211 only accepts a decimal integer.
212 The entity_name field gives an ASCII string identifying the glyph which
214 the postprocessor uses to print that glyph. This field is optional and
215 is currently used by grops to build sub-encoding arrays for PS fonts
216 containing more than 256 glyphs. (It has also been used for grohtml's
217 entity names but for efficiency reasons this data is now compiled di‐
218 rectly into grohtml.)
219 Anything on the line after the encoding field or ‘--’ are ignored.
221 The metrics field has the form (in one line; it is broken here for the
223 sake of readability):
224 width[,height[,depth[,italic-correction
226 [,left-italic-correction[,subscript-correction]]]]]
227 There must not be any spaces between these subfields. Missing sub‐
229 fields are assumed to be 0. The subfields are all decimal integers.
230 Since there is no associated binary format, these values are not re‐
231 quired to fit into a variable of type char as they are in ditroff. The
232 width subfields gives the width of the glyph. The height subfield
233 gives the height of the glyph (upwards is positive); if a glyph does
234 not extend above the baseline, it should be given a zero height, rather
235 than a negative height. The depth subfield gives the depth of the
236 glyph, that is, the distance below the baseline to which the glyph ex‐
237 tends (downwards is positive); if a glyph does not extend below the
238 baseline, it should be given a zero depth, rather than a negative
239 depth. The italic-correction subfield gives the amount of space that
240 should be added after the glyph when it is immediately to be followed
241 by a glyph from a roman font. The left-italic-correction subfield
242 gives the amount of space that should be added before the glyph when it
243 is immediately to be preceded by a glyph from a roman font. The sub‐
244 script-correction gives the amount of space that should be added after
245 a glyph before adding a subscript. This should be less than the italic
246 correction.
247 A line in the charset section can also have the format
249 name "
251 This indicates that name is just another name for the glyph mentioned
253 in the preceding line.
254 The word kernpairs starts the kernpairs section. This contains a se‐
256 quence of lines of the form:
257 c1 c2 n
259 This means that when glyph c1 appears next to glyph c2 the space be‐
261 tween them should be increased by n. Most entries in kernpairs section
262 have a negative value for n.
263
265 /usr/share/groff/1.22.4/font/devname/DESC
266 Device description file for device name.
267 /usr/share/groff/1.22.4/font/devname/F
269 Font file for font F of device name.
270
272 groff_out(5), troff(1), addftinfo(1), afmtodit(1)
273 A man page name(n) of section n can be viewed either with
275 $ man n name
276 for text mode or
277 $ groffer n name
278 for graphical mode (default is PDF mode).
279groff 1.22.4 20 January 2022 GROFF_FONT(5)