term(4) 						     Kernel Interfaces Manual							   term(4)

NAME

       term - Terminal driver tables for nroff

DESCRIPTION

       The  nroff(1) command uses driver tables to customize its output for various types of output devices.  These driver tables are written as C
       programs and compiled and installed in /usr/share/lib/term/tabname.  The name specifier is the name of a terminal type as used  with  nroff
       -Tname.	The structure of the tables is as follows:

       #define INCH 240 struct {
	int bset;
	int breset;
	int Hor;
	int Vert;
	int Newline;
	int Char;
	int Em;
	int Halfline;
	int Adj;
	char *twinit;
	char *twrest;
	char *twnl;
	char *hlr;
	char *hlf;
	char *flr;
	char *bdon;
	char *bdoff;
	char *ploton;
	char *plotoff;
	char *up;
	char *down;
	char *right;
	char *left;
	char *codetab[256-32];
	char *zzz; } t;

       The  fields  have the following meanings: Bits to set in the c_oflag field of the termio structure before output.  For further information,
       see tty(7).  Bits to reset in the c_oflag field of the termio structure before output.  Horizontal resolution  in  fractions  of  an  inch.
       Vertical  resolution in fractions of an inch.  Space moved by a newline (linefeed) character in fractions of an inch.  Quantum of character
       sizes in fractions of an inch (that is, a character is a multiple of Char units wide).  Size of an em in fractions of an inch.  Space moved
       by  a half-linefeed (or half-reverse-linefeed) character in fractions of an inch.  Quantum of white space in fractions of an inch (that is,
       white spaces are a multiple of Adj units wide).

	      Note: if this value is less than the size of the space character (in units of Char; see the following fields for how  the  sizes	of
	      characters  are  defined), nroff outputs fractional spaces using plot mode.  Also, if nroff is used with the -e flag, it sets Adj to
	      equal Hor.  The set of characters used to initialize the terminal in a mode suitable for nroff The set of characters used to restore
	      the  terminal  to  normal  mode.	 The set of characters used to move down one line.  The set of characters used to move up one-half
	      line.  The set of characters used to move down one-half line.  The set of characters used to move up one line.  The set  of  charac-
	      ters  used  to  turn on hardware boldface mode, if any.  The set of characters used to turn off hardware boldface mode, if any.  The
	      set of characters used to turn on hardware italics mode, if any.	The set of characters used to turn off hardware italics  mode,	if
	      any.   The set of characters used to turn on hardware plot mode (for Diablo type mechanisms), if any.  The set of characters used to
	      turn off hardware plot mode (for Diablo type mechanisms), if any.  The set of characters used to move up one resolution unit  (Vert)
	      in  plot mode, if any.  The set of characters used to move down one resolution unit (Vert) in plot mode, if any.	The set of charac-
	      ters used to move right one resolution unit (Hor) in plot mode, if any.  The set of characters used to move left one resolution unit
	      (Hor)  in  plot  mode,  if any.  Definition of characters needed to print an nroff character on the terminal.  The first byte is the
	      number of character units (Char) needed to hold the character; that is, ``01'' is one unit wide, ``02'' is two units	wide,  and
	      so on.  The high-order bit (0200) is on if the character is to be underlined in underline mode (.ul).  The rest of the bytes are the
	      characters used to produce the character in question.  If the character has the sign (0200) bit on, it is a code to move the  termi-
	      nal in plot mode.  It is encoded as follows: Vertical motion Horizontal motion Negative (up or left) motion Positive (down or right)
	      motion Number of such motions to make A zero terminator at the end.

       All quantities that are in units of fractions of an inch should be expressed as INCH*num/denom, where num and denom  are  respectively  the
       numerator and denominator of the fraction; that is, 1/48 of an inch would be written as ``INCH1/48''.

       If any sequence of characters does not pertain to the output device, that sequence should be given as a null string.

       The  source code for the terminal name is in /usr/share/lib/term/tabname.  When a new terminal type is added, the makefile Makefile.install
       in that directory should be updated.

   Building New nroff Drivers
       The /usr/share/lib/term/mktab.o object module is an nroff compiler-independent driver table generator tool.  It is intended to be  used	as
       follows: cc -o /tmp/mktab tabxxx.c mktab.o, /tmp/mktab > tabxx

   Default nroff Drivers
       The  following  nroff  drivers  are provided: Dumb 10-pitch printer with no halfline or upline capability.  Generic crt terminal (linked to
       lpr).  LN03S ASCII printer.  VT100 crt terminal.  Default pseudo-printer device for the man(1)  and  catman(8)  commands.   NOTE:   The	lp
       driver as supplied by Compaq is linked to the vt100 device.  Your system administrator can change the definition of lp to another device.

FILES

       Driver tables Source file for the driver tables

RELATED INFORMATION

       tty(7) delim off

																	   term(4)