Command Section

       groff_font - format of groff device and font description	files

       The groff font format is	roughly	a superset of the ditroff font format.
       The font	files for device name  are  stored  in	a  directory  devname.
       There  are two types of file: a device description 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.

	      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 will be mounted in	the font positions m+1,...,m+n
	      where m is the number of styles.	This command may  extend  over
	      more  than  one line.  A font name of 0 will cause 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 PostScript input.  Under	GNU/Linux this is usu-
	      ally 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
	      spaces  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  picas.  Example:
	      12c,235p.	 An argument which  starts  with  a  digit  is	always
	      treated  as a custom paper format.  papersize sets both the ver-
	      tical 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.

	      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	0
	      This  means  that	 the  device  has fonts	at s1, s2,	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 pointsizes.	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  will  be  associated  with	styles

	      This  means that the postprocessor can handle the	t and u	output

       unitwidth n
	      Quantities in the	font files are	given  in  machine  units  for
	      fonts whose point	size is	n scaled points.

	      Make  the	 font handling module always return unscaled character
	      widths.  Needed for the grohtml device.

	      This command indicates that troff	should encode named characters
	      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  key-
       words  (or  even	 additional  ones) are used by postprocessors to store
       arbitrary information about the device.

       Here a list of obsolete keywords	which are recognized by	groff but com-
       pletely ignored:	spare1,	spare2,	biggestfont.

   Font	file format
       A font file has two sections.  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]
	      Characters  lig1,	 lig2, ..., lign are ligatures;	possible liga-
	      tures 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 characters of	the font have a	slant of n degrees.  (Positive
	      means forward.)

       spacewidth n
	      The normal width of a space is n.

	      The  font	 is  special;  this  means  that  when	a character is
	      requested	that is	not present in the current font,  it  will  be
	      searched for in any special fonts	that are mounted.

       Other  commands	are ignored by troff but may be	used by	postprocessors
       to store	arbitrary information 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
       character.  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 character: if name is a single character 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 char-
       acter \[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 special characters can't	be accessed as \c; the
       only  exception	is `\-'	which is identical to `\[-]'.  The name	--- is
       special and indicates that the character	is  unnamed;  such  characters
       can only	be used	by means of the	\N escape sequence in troff.

       Groff supports eight-bit	characters; however some utilities have	diffi-
       culties with eight-bit characters.  For this reason, there is a conven-
       tion  that  the	name charn is equivalent to the	single character whose
       code is n.  For example,	char163	would be equivalent to	the  character
       with code 163 which is the pounds sterling sign in ISO Latin-1.

       The type	field gives the	character type:

       1      means the	character has a	descender, for example,	p;

       2      means the	character has an ascender, for example,	b;

       3      means  the  character  has both an ascender and a	descender, for
	      example, (.

       The code	field gives the	code which the postprocessor uses to print the
       character.  The character 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 will be interpreted	as octal; if it	starts with 0x
       or 0X it	will be	intepreted 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 the character.  This field is  optional
       and  has	 been introduced so that the html device driver	can encode its
       character set.  For example, the	character `\[Po]'  is  represented  as
       `£' in html 4.0.

       Anything	 on the	line after the encoding	field resp. after `--' will be

       The metrics field has the form (in one line; it is broken here for  the
       sake of readability):


       There  must  not	 be  any spaces	between	these subfields.  Missing sub-
       fields 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 character.  The height sub-
       field gives the height of the character (upwards	 is  positive);	 if  a
       character 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  character, that is, the distance	below the lowest point
       below the baseline to which the character extends (downwards  is	 posi-
       tive);  if  a  character	 does  not extend below	above 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 character when it is immediately	to be  followed	 by  a
       character from a	roman font.  The left-italic-correction	subfield gives
       the amount of space that	should be added	before the character  when  it
       is  immediately	to  be preceded	by a character from a roman font.  The
       subscript-correction gives the amount of	space  that  should  be	 added
       after  a	character 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  character  men-
       tioned 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 character c1 appears  next	to  character  c2  the
       space between them should be increased by n.  Most entries in kernpairs
       section will have a negative value for n.

	      Device description file for device name.

	      Font file	for font F of device name.

       groff_out(5), troff(1).

Groff Version 1.19.2	       4 September 2005			 GROFF_FONT(5)
Command Section