man font () - external format for fonts and subfonts
NAME
font, subfont - external format for fonts and subfonts
SYNOPSIS
#include <libc.h> #include <libg.h>
DESCRIPTION
Fonts and subfonts are described in cachechars(3g).
External fonts are described by a plain text file that can be read using rdfontfile. The format of the file is a header followed by any number of subfont range specifications. The header contains two numbers: the height and the ascent. The height is the inter-line spacing and the ascent is the distance from the top of the line to the baseline. These numbers are chosen to display consistently all the subfonts of the font. A subfont range specification contains two numbers and a font name. The numbers are the inclusive range of characters covered by the subfont, and name specifies the name of an X font suitable for getsubfont. The minimum number of a covered range is mapped to the first defined character of the corresponding subfont. Each field must be followed by some white space. Each numeric field may be C-format decimal, octal, or hexadecimal.
BUGS
Some X font names contain spaces which will terminate the field. For some fonts this can be worked around by replacing the spaces with characters in an attempt to fool the X font name pattern matching mechanism.