Ubuntu Manpage: setfont - load EGA/VGA console screen font

NAME

       setfont - load EGA/VGA console screen font

SYNOPSIS

       setfont  [-O font+umap.orig] [-o font.orig] [-om cmap.orig] [-ou umap.orig] [-N] [font.new
       ...] [-m cmap] [-u umap] [-C console] [-hH] [-f] [-v] [-V]

DESCRIPTION

       The setfont command reads a font from the file font.new and  loads  it  into  the  EGA/VGA
       character  generator,  and optionally outputs the previous font.  It can also load various
       mapping tables and output the previous versions.

       If no args are given (or only the option -N for some number N), then a default (8xN)  font
       is  loaded (see below).  One may give several small fonts, all containing a Unicode table,
       and setfont will combine them and load the union.  Typical use:

       setfont
              Load a default font.

       setfont drdos8x16
              Load a given font (here the 448-glyph drdos font).

       setfont cybercafe -u cybercafe
              Load a given font that does not have a Unicode map and provide one explicitly.

       setfont LatArCyrHeb-19 -m 8859-2
              Load a given font (here a 512-glyph font  combining  several  character  sets)  and
              indicate that one's local character set is ISO 8859-2.

       Note:  if  a  font  has  more  than  256  glyphs,  only  8  out  of  16 colors can be used
       simultaneously. It can make console perception worse (loss  of  intensity  and  even  some
       colors).

FONT FORMATS

       The  standard  Linux  font  format  is  the  PSF  font.   It  has a header describing font
       properties like character size, followed by the glyph bitmaps, optionally  followed  by  a
       Unicode  mapping  table giving the Unicode value for each glyph.  Several other (obsolete)
       font formats are recognized.  If the input file has code page format (probably with suffix
       .cp),  containing  three fonts with sizes e.g. 8x8, 8x14 and 8x16, then one of the options
       -8 or -14 or -16 must be used to select one.  Raw font files  are  binary  files  of  size
       256*N bytes, containing bit images for each of 256 characters, one byte per scan line, and
       N bytes per character (0 < N <= 32).  Most fonts have a width of  8  bits,  but  with  the
       framebuffer device (fb) other widths can be used.

FONT HEIGHT

       The program setfont has no built-in knowledge of VGA video modes, but just asks the kernel
       to load the character ROM of the video card with certain  bitmaps.  However,  since  Linux
       1.3.1  the  kernel  knows  enough  about  EGA/VGA  video  modes to select a different line
       distance. The default character height will be the number N  inferred  from  the  font  or
       specified  by  option.  However, the user can specify a different character height H using
       the -h option.

CONSOLE MAPS

Several mappings are involved in the path from user program output to console display. If
the console is in utf8 mode (see unicode_start(1)) then the kernel expects that user
program output is coded as UTF-8 (see utf-8(7)), and converts that to Unicode (ucs2).
Otherwise, a translation table is used from the 8-bit program output to 16-bit Unicode
values. Such a translation table is called a Unicode console map. There are four of them:
three built into the kernel, the fourth settable using the -m option of setfont. An
escape sequence chooses between these four tables; after loading a cmap, setfont will
output the escape sequence Esc ( K that makes it the active translation.

Suitable arguments for the -m option are for example 8859-1, 8859-2, ..., 8859-15, cp437,
..., cp1250.

Given the Unicode value of the symbol to be displayed, the kernel finds the right glyph in
the font using the Unicode mapping info of the font and displays it.

Old fonts do not have Unicode mapping info, and in order to handle them there are direct-
to-font maps (also loaded using -m) that give a correspondence between user bytes and font
positions. The most common correspondence is the one given in the file trivial (where
user byte values are used directly as font positions). Other correspondences are
sometimes preferable since the PC video hardware expects line drawing characters in
certain font positions.

Giving a -m none argument inhibits the loading and activation of a mapping table. The
previous console map can be saved to a file using the -om file option. These options of
setfont render mapscrn(8) obsolete. (However, it may be useful to read that man page.)

UNICODE FONT MAPS

       The correspondence between the glyphs in the font and Unicode values  is  described  by  a
       Unicode mapping table.  Many fonts have a Unicode mapping table included in the font file,
       and an explicit table can be indicated using the -u option. The program setfont will  load
       such  a  Unicode  mapping  table, unless a -u none argument is given. The previous Unicode
       mapping table will be saved as part of the saved font file when the -O option is used.  It
       can  be  saved  to  a  separate  file using the -ou file option.  These options of setfont
       render loadunimap(8) obsolete.

       The Unicode mapping table should assign  some  glyph  to  the  `missing  character'  value
       U+fffd,  otherwise  missing characters are not translated, giving a usually very confusing
       result.

       Usually no mapping table is needed, and a Unicode mapping table is  already  contained  in
       the font (sometimes this is indicated by the .psfu extension), so that most users need not
       worry about the precise meaning and functioning of these mapping tables.

       One may add a Unicode mapping table to a psf font using psfaddtable(1).

OPTIONS

       -h H   Override font height.

       -d     Doubles the size of the font, by replicating  all  of  its  pixels  vertically  and
              horizontally.   This  is  suitable  for  high pixel density (e.g. "4k") displays on
              which the standard fonts are too  small  to  be  easily  legible.   Due  to  kernel
              limitations, this is suitable only for 16x16 or smaller fonts.

       -m file
              Load console map or Unicode console map from file.

       -o file
              Save previous font in file.

       -O file
              Save previous font and Unicode map in file.

       -om file
              Store console map in file.

       -ou file
              Save previous Unicode map in file.

       -u file
              Load Unicode table describing the font from file.

       -C console
              Set the font for the indicated console. (May require root permissions.)

       -f     Force-load unicode map: Setfont`issues the system call to load the unicode map even
              if the specified map is empty.  This may be useful in unusual cases.

       -v     Be verbose.

       -V     Print version and exit.

NOTE

       PC video hardware allows one to use the "intensity" bit either to indicate brightness,  or
       to  address  512  (instead  of  256) glyphs in the font. So, if the font has more than 256
       glyphs, the console will be reduced to 8 (instead of 16) colors.

FILES

       /usr/share/consolefonts
              The default font directory.

       /usr/share/unimaps
              The default directory for Unicode maps.

       /usr/share/consoletrans
              The default directory for screen mappings.

       The default font is a file default (or default8xN if the -N  option  was  given  for  some
       number N) perhaps with suitable extension (like .psf).