tdef.h

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

struct Diver {		/* diversion */
	Offset	op;
	int	dnl;
	int	dimac;
	int	ditrap;
	int	ditf;
	int	alss;
	int	blss;
	int	nls;
	int	mkline;
	int	maxl;
	int	hnl;
	int	curd;
};

struct Stack {		/* stack frame */
	int	nargs;
	Stack	*pframe;
	Offset	pip;
	int	pnchar;
	Tchar	prchar;
	int	ppendt;
	Tchar	pch;
	Tchar	*lastpbp;
	int	mname;
};

extern	Stack	s;

struct Divsiz {
	int dix;
	int diy;
};

struct Contab {		/* command or macro */
	unsigned int	rq;
	Contab	*link;
	void	(*f)(void);
	Offset	mx;
	Offset	emx;
	Divsiz	*divsiz;
};

#define	C(a,b)	{a, 0, b, 0, 0}		/* how to initialize a contab entry */

extern	Contab	contab[NM];

struct Numtab {	/* number registers */
	unsigned int	r;		/* name */
	int	val;
	short	fmt;
	short	inc;
	Numtab	*link;
};

extern	Numtab	numtab[NN];

#define	PN	0
#define	NL	1
#define	YR	2
#define	HP	3
#define	CT	4
#define	DN	5
#define	MO	6
#define	DY	7
#define	DW	8
#define	LN	9
#define	DL	10
#define	ST	11
#define	SB	12
#define	CD	13
#define	PID	14

struct	Wcache {	/* width cache, indexed by character */
	short	fontpts;
	short	width;
};

struct	Tbuf {		/* growable Tchar buffer */
	Tchar *_bufp;
	unsigned int _size;
};

/* the infamous environment block */

#define	ics	envp->_ics
#define	sps	envp->_sps
#define	spacesz	envp->_spacesz
#define	lss	envp->_lss
#define	lss1	envp->_lss1
#define	ll	envp->_ll
#define	ll1	envp->_ll1
#define	lt	envp->_lt
#define	lt1	envp->_lt1
#define	ic	envp->_ic
#define	icf	envp->_icf
#define	chbits	envp->_chbits
#define	spbits	envp->_spbits
#define	nmbits	envp->_nmbits
#define	apts	envp->_apts
#define	apts1	envp->_apts1
#define	pts	envp->_pts
#define	pts1	envp->_pts1
#define	font	envp->_font
#define	font1	envp->_font1
#define	ls	envp->_ls
#define	ls1	envp->_ls1
#define	ad	envp->_ad
#define	nms	envp->_nms
#define	ndf	envp->_ndf
#define	nmwid	envp->_nmwid
#define	fi	envp->_fi
#define	cc	envp->_cc
#define	c2	envp->_c2
#define	ohc	envp->_ohc
#define	tdelim	envp->_tdelim
#define	hyf	envp->_hyf
#define	hyoff	envp->_hyoff
#define	hyphalg	envp->_hyphalg
#define	un1	envp->_un1
#define	tabc	envp->_tabc
#define	dotc	envp->_dotc
#define	adsp	envp->_adsp
#define	adrem	envp->_adrem
#define	lastl	envp->_lastl
#define	nel	envp->_nel
#define	admod	envp->_admod
#define	wordp	envp->_wordp
#define	spflg	envp->_spflg
#define	linep	envp->_linep
#define	wdend	envp->_wdend
#define	wdstart	envp->_wdstart
#define	wne	envp->_wne
#define	ne	envp->_ne
#define	nc	envp->_nc
#define	nb	envp->_nb
#define	lnmod	envp->_lnmod
#define	nwd	envp->_nwd
#define	nn	envp->_nn
#define	ni	envp->_ni
#define	ul	envp->_ul
#define	cu	envp->_cu
#define	ce	envp->_ce
#define	in	envp->_in
#define	in1	envp->_in1
#define	un	envp->_un
#define	wch	envp->_wch
#define	pendt	envp->_pendt
#define	pendw	envp->_pendw
#define	pendnf	envp->_pendnf
#define	spread	envp->_spread
#define	it	envp->_it
#define	itmac	envp->_itmac
#define	hyptr	envp->_hyptr
#define	tabtab	envp->_tabtab
#define	line	envp->_line._bufp
#define	lnsize	envp->_line._size
#define	word	envp->_word._bufp
#define wdsize	envp->_word._size

#define oline	_oline._bufp
#define olnsize	_oline._size

/*
 * Note:
 * If this structure changes in ni.c, you must change
 * this as well, and vice versa.
 */

struct Env {
	int	_ics;
	int	_sps;
	int	_spacesz;
	int	_lss;
	int	_lss1;
	int	_ll;
	int	_ll1;
	int	_lt;
	int	_lt1;
	Tchar	_ic;
	int	_icf;
	Tchar	_chbits;
	Tchar	_spbits;
	Tchar	_nmbits;
	int	_apts;
	int	_apts1;
	int	_pts;
	int	_pts1;
	int	_font;
	int	_font1;
	int	_ls;
	int	_ls1;
	int	_ad;
	int	_nms;
	int	_ndf;
	int	_nmwid;
	int	_fi;
	int	_cc;
	int	_c2;
	int	_ohc;
	int	_tdelim;
	int	_hyf;
	int	_hyoff;
	int	_hyphalg;
	int	_un1;
	int	_tabc;
	int	_dotc;
	int	_adsp;
	int	_adrem;
	int	_lastl;
	int	_nel;
	int	_admod;
	Tchar	*_wordp;
	int	_spflg;
	Tchar	*_linep;
	Tchar	*_wdend;
	Tchar	*_wdstart;
	int	_wne;
	int	_ne;
	int	_nc;
	int	_nb;
	int	_lnmod;
	int	_nwd;
	int	_nn;
	int	_ni;
	int	_ul;
	int	_cu;
	int	_ce;
	int	_in;
	int	_in1;
	int	_un;
	int	_wch;
	int	_pendt;
	Tchar	*_pendw;
	int	_pendnf;
	int	_spread;
	int	_it;
	int	_itmac;
	Tchar	*_hyptr[NHYP];
	long	_tabtab[NTAB];
	Tbuf	_line;
	Tbuf	_word;
};

extern	Env	env[];
extern	Env	*envp;

enum {	MBchar = 'U', Troffchar = 'C', Number = 'N', Install = 'i', Lookup = 'l' };
	/* U => utf, for instance;  C => \(xx, N => \N'...' */



struct Chwid {	/* data on one character */
	Ushort	num;		/* character number:
					0 -> not on this font
					>= ALPHABET -> its number among all Cxy's */
	Ushort	code;		/* char code for actual device.  used for \N */
	char	*str;		/* code string for nroff */
	Uchar	wid;		/* width */
	Uchar	kern;		/* ascender/descender */
};

struct Font {	/* characteristics of a font */
	int	name;		/* int name, e.g., BI (2 chars) */
	char	longname[64];	/* long name of this font (e.g., "Bembo" */
	char	*truename;	/* path name of table if not in standard place */
	int	nchars;		/* number of width entries for this font */
	char	specfont;	/* 1 == special font */
	int	spacewidth;	/* width of space on this font */
	int	defaultwidth;	/* default width of characters on this font */
	Chwid	*wp;		/* widths, etc., of the real characters */
	char	ligfont;	/* 1 == ligatures exist on this font */
};

/* ligatures, ORed into ligfont */

#define	LFF	01
#define	LFI	02
#define	LFL	04
#define	LFFI	010
#define	LFFL	020

/* tracing modes */
#define TRNARGS	01		/* trace legality of numeric arguments */
#define TRREQ	02		/* trace requests */
#define TRMAC	04		/* trace macros */
#define RQERR	01		/* processing request/macro */

/* typewriter driving table structure */


extern	Term	t;
struct Term {
	int	bset;		/* these bits have to be on */
	int	breset;		/* these bits have to be off */
	int	Hor;		/* #units in minimum horiz motion */
	int	Vert;		/* #units in minimum vert motion */
	int	Newline;	/* #units in single line space */
	int	Char;		/* #units in character width */
	int	Em;		/* ditto */
	int	Halfline;	/* half line units */
	int	Adj;		/* minimum units for horizontal adjustment */
	char	*twinit;	/* initialize terminal */
	char	*twrest;	/* reinitialize terminal */
	char	*twnl;		/* terminal sequence for newline */
	char	*hlr;		/* half-line reverse */
	char	*hlf;		/* half-line forward */
	char	*flr;		/* full-line reverse */
	char	*bdon;		/* turn bold mode on */
	char	*bdoff;		/* turn bold mode off */
	char	*iton;		/* turn italic mode on */
	char	*itoff;		/* turn italic mode off */
	char	*ploton;	/* turn plot mode on */
	char	*plotoff;	/* turn plot mode off */
	char	*up;		/* sequence to move up in plot mode */
	char	*down;		/* ditto */
	char	*right;		/* ditto */
	char	*left;		/* ditto */

	Font	tfont;		/* widths and other info, as in a troff font */
};

extern	Term	t;

/*
 * for error reporting; keep track of escapes/requests with numeric arguments
 */
struct Numerr {
	char	type;	/* request or escape? */
	char	esc;	/* was escape sequence named esc */
	char	escarg;	/* argument of esc's like \D'l' */
	unsigned int	req;	/* was request or macro named req */
};