From decwrl!elroy.jpl.nasa.gov!usc!cs.utexas.edu!uunet!allbery Sat Mar 10 15:34:25 PST 1990
Article 1387 of comp.sources.misc:
Path: decwrl!elroy.jpl.nasa.gov!usc!cs.utexas.edu!uunet!allbery
From: dmt@pegasus.ATT.COM (Dave Tutelman)
Newsgroups: comp.sources.misc
Subject: v11i012: Stevie 3.69a - 4/6
Message-ID: <80852@uunet.UU.NET>
Date: 10 Mar 90 19:42:55 GMT
Sender: allbery@uunet.UU.NET
Organization: AT&T Bell Labs - Lincroft, NJ
Lines: 2453
Approved: allbery@uunet.UU.NET (Brandon S. Allbery - comp.sources.misc)

Posting-number: Volume 11, Issue 12
Submitted-by: dmt@pegasus.ATT.COM (Dave Tutelman)
Archive-name: stevie3.69a/part04

: This is a shar archive.  Extract with sh, not csh.
: The rest of this file will extract:
: param.c ptrfunc.c regexp.c regsub.c screen.c
echo extracting - param.c
sed 's/^X//' > param.c << '!EOR!'
X/* $Header: /nw/tony/src/stevie/src/RCS/param.c,v 1.10 89/08/02 10:59:10 tony Exp $
X *
X * Code to handle user-settable parameters. This is all pretty much table-
X * driven. To add a new parameter, put it in the params array, and add a
X * macro for it in param.h. If it's a numeric parameter, add any necessary
X * bounds checks to doset(). String parameters aren't currently supported.
X */
X
X#include "stevie.h"
X
Xstruct	param	params[] = {
X
X	{ "tabstop",	"ts",		8,	P_NUM },
X	{ "scroll",	"scroll",	12,	P_NUM },
X	{ "report",	"report",	5,	P_NUM },
X	{ "lines",	"lines",	25,	P_NUM },
X
X	{ "vbell",	"vb",		TRUE,	P_BOOL },
X	{ "showmatch",	"sm",		FALSE,	P_BOOL },
X	{ "wrapscan",	"ws",		TRUE,	P_BOOL },
X	{ "errorbells",	"eb",		FALSE,	P_BOOL },
X	{ "showmode",	"mo",		FALSE,	P_BOOL },
X	{ "backup",	"bk",		FALSE,	P_BOOL },
X	{ "return",	"cr",		TRUE,	P_BOOL },
X	{ "list",	"list",		FALSE,	P_BOOL },
X	{ "ignorecase",	"ic",		FALSE,	P_BOOL },
X	{ "autoindent",	"ai",		FALSE,	P_BOOL },
X	{ "number",	"nu",		FALSE,	P_BOOL },
X	{ "modelines",	"ml",		FALSE,	P_BOOL },
X	{ "tildeop",	"to",		FALSE,	P_BOOL },
X	{ "terse",	"terse",	FALSE,	P_BOOL },
X	{ "tagstack",	"tg",		FALSE,	P_BOOL },
X	{ "color",	"co",		-1,	P_NUM  },
X	{ "",		"",		0,	0, }		/* end marker */
X
X};
X
Xstatic	void	showparms();
X
Xvoid
Xdoset(arg)
Xchar	*arg;		/* parameter string */
X{
X	register int	i;
X	register char	*s;
X	bool_t	did_lines = FALSE;
X	bool_t	state = TRUE;		/* new state of boolean parms. */
X
X	if (arg == NULL) {
X		showparms(FALSE);
X		return;
X	}
X	if (strncmp(arg, "all", 3) == 0) {
X		showparms(TRUE);
X		return;
X	}
X	if (strncmp(arg, "no", 2) == 0) {
X		state = FALSE;
X		arg += 2;
X	}
X
X	for (i=0; params[i].fullname[0] != NUL ;i++) {
X		s = params[i].fullname;
X		if (strncmp(arg, s, strlen(s)) == 0)	/* matched full name */
X			break;
X		s = params[i].shortname;
X		if (strncmp(arg, s, strlen(s)) == 0)	/* matched short name */
X			break;
X	}
X
X	if (params[i].fullname[0] != NUL) {	/* found a match */
X		if (params[i].flags & P_NUM) {
X			did_lines = (i == P_LI);
X			if (arg[strlen(s)] != '=' || state == FALSE)
X				emsg("Invalid set of numeric parameter");
X			else {
X				params[i].value = atoi(arg+strlen(s)+1);
X				params[i].flags |= P_CHANGED;
X				if (i==P_CO)  setcolor (P(P_CO));
X			}
X		} else /* boolean */ {
X			if (arg[strlen(s)] == '=')
X				emsg("Invalid set of boolean parameter");
X			else {
X				params[i].value = state;
X				params[i].flags |= P_CHANGED;
X			}
X		}
X	} else
X		emsg("Unrecognized 'set' option");
X
X	/*
X	 * Update the screen in case we changed something like "tabstop"
X	 * or "list" that will change its appearance.
X	 */
X	updatescreen();
X
X	if (did_lines) {
X		Rows = P(P_LI);
X		P(P_LI) = Rows = setrows( Rows );
X					/* setrows() is system-dependent.
X					 * This assures no impossible values
X					 * will be set.
X					 */
X		if (screenalloc() == -1) return;	/* allocate new screen buffers */
X		screenclear();
X		updatescreen();
X	}
X	/*
X	 * Check the bounds for numeric parameters here
X	 */
X	if (P(P_TS) <= 0 || P(P_TS) > 32) {
X		emsg("Invalid tab size specified");
X		P(P_TS) = 8;
X		return;
X	}
X
X	if (P(P_SS) <= 0 || P(P_SS) > Rows) {
X		emsg("Invalid scroll size specified");
X		P(P_SS) = 12;
X		return;
X	}
X
X#ifndef	TILDEOP
X	if (P(P_TO)) {
X		emsg("Tilde-operator not enabled");
X		P(P_TO) = FALSE;
X		return;
X	}
X#endif
X	/*
X	 * Check for another argument, and call doset() recursively, if
X	 * found. If any argument results in an error, no further
X	 * parameters are processed.
X	 */
X	while (*arg != ' ' && *arg != '\t') {	/* skip to next white space */
X		if (*arg == NUL)
X			return;			/* end of parameter list */
X		arg++;
X	}
X	while (*arg == ' ' || *arg == '\t')	/* skip to next non-white */
X		arg++;
X
X	if (*arg)
X		doset(arg);	/* recurse on next parameter */
X}
X
Xstatic	void
Xshowparms(all)
Xbool_t	all;	/* show ALL parameters */
X{
X	register struct	param	*p;
X	char	buf[64];
X
X	gotocmd(TRUE, 0);
X	outstr("Parameters:\r\n");
X
X	for (p = &params[0]; p->fullname[0] != NUL ;p++) {
X		if (!all && ((p->flags & P_CHANGED) == 0))
X			continue;
X		if (p->flags & P_BOOL)
X			sprintf(buf, "\t%s%s\r\n",
X				(p->value ? "" : "no"), p->fullname);
X		else
X			sprintf(buf, "\t%s=%d\r\n", p->fullname, p->value);
X
X		outstr(buf);
X	}
X	wait_return();
X}
!EOR!
echo extracting - ptrfunc.c
sed 's/^X//' > ptrfunc.c << '!EOR!'
X/* $Header: /nw/tony/src/stevie/src/RCS/ptrfunc.c,v 1.5 89/03/11 22:43:12 tony Exp $
X *
X * The routines in this file attempt to imitate many of the operations
X * that used to be performed on simple character pointers and are now
X * performed on LPTR's. This makes it easier to modify other sections
X * of the code. Think of an LPTR as representing a position in the file.
X * Positions can be incremented, decremented, compared, etc. through
X * the functions implemented here.
X */
X
X#include "stevie.h"
X
X/*
X * inc(p)
X *
X * Increment the line pointer 'p' crossing line boundaries as necessary.
X * Return 1 when crossing a line, -1 when at end of file, 0 otherwise.
X */
Xint
Xinc(lp)
Xregister LPTR	*lp;
X{
X	register char	*p;
X
X	if (lp && lp->linep)
X		p = &(lp->linep->s[lp->index]);
X	else
X		return -1;
X
X	if (*p != NUL) {			/* still within line */
X		lp->index++;
X		return ((p[1] != NUL) ? 0 : 1);
X	}
X
X	if (lp->linep->next != Fileend->linep) {  /* there is a next line */
X		lp->index = 0;
X		lp->linep = lp->linep->next;
X		return 1;
X	}
X
X	return -1;
X}
X
X/*
X * dec(p)
X *
X * Decrement the line pointer 'p' crossing line boundaries as necessary.
X * Return 1 when crossing a line, -1 when at start of file, 0 otherwise.
X */
Xint
Xdec(lp)
Xregister LPTR	*lp;
X{
X	if (lp->index > 0) {			/* still within line */
X		lp->index--;
X		return 0;
X	}
X
X	if (lp->linep->prev != Filetop->linep) { /* there is a prior line */
X		lp->linep = lp->linep->prev;
X		lp->index = strlen(lp->linep->s);
X		return 1;
X	}
X
X	lp->index = 0;				/* stick at first char */
X	return -1;				/* at start of file */
X}
X
X/*
X * gchar(lp) - get the character at position "lp"
X */
Xint
Xgchar(lp)
Xregister LPTR	*lp;
X{
X	if (lp && lp->linep)
X		return (lp->linep->s[lp->index]);
X	else
X		return 0;
X}
X
X/*
X * pchar(lp, c) - put character 'c' at position 'lp'
X */
Xvoid
Xpchar(lp, c)
Xregister LPTR	*lp;
Xchar	c;
X{
X	lp->linep->s[lp->index] = c;
X}
X
X/*
X * pswap(a, b) - swap two position pointers
X */
Xvoid
Xpswap(a, b)
Xregister LPTR	*a, *b;
X{
X	LPTR	tmp;
X
X	tmp = *a;
X	*a  = *b;
X	*b  = tmp;
X}
X
X/*
X * Position comparisons
X */
X
Xbool_t
Xlt(a, b)
Xregister LPTR	*a, *b;
X{
X	register int	an, bn;
X
X	an = LINEOF(a);
X	bn = LINEOF(b);
X
X	if (an != bn)
X		return (an < bn);
X	else
X		return (a->index < b->index);
X}
X
X#if 0
Xbool_t
Xgt(a, b)
XLPTR	*a, *b;
X{
X	register int an, bn;
X
X	an = LINEOF(a);
X	bn = LINEOF(b);
X
X	if (an != bn)
X		return (an > bn);
X	else
X		return (a->index > b->index);
X}
X#endif
X
Xbool_t
Xequal(a, b)
Xregister LPTR	*a, *b;
X{
X	return (a->linep == b->linep && a->index == b->index);
X}
X
Xbool_t
Xltoreq(a, b)
Xregister LPTR	*a, *b;
X{
X	return (lt(a, b) || equal(a, b));
X}
X
X#if 0
Xbool_t
Xgtoreq(a, b)
XLPTR	*a, *b;
X{
X	return (gt(a, b) || equal(a, b));
X}
X#endif
!EOR!
echo extracting - regexp.c
sed 's/^X//' > regexp.c << '!EOR!'
X/* $Header: /nw/tony/src/stevie/src/RCS/regexp.c,v 1.5 89/07/07 16:27:11 tony Exp $
X *
X * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
X *
X * This is NOT the original regular expression code as written by
X * Henry Spencer. This code has been modified specifically for use
X * with the STEVIE editor, and should not be used apart from compiling
X * STEVIE. If you want a good regular expression library, get the
X * original code. The copyright notice that follows is from the
X * original.
X *
X * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
X *
X *
X * regcomp and regexec -- regsub and regerror are elsewhere
X *
X *	Copyright (c) 1986 by University of Toronto.
X *	Written by Henry Spencer.  Not derived from licensed software.
X *
X *	Permission is granted to anyone to use this software for any
X *	purpose on any computer system, and to redistribute it freely,
X *	subject to the following restrictions:
X *
X *	1. The author is not responsible for the consequences of use of
X *		this software, no matter how awful, even if they arise
X *		from defects in it.
X *
X *	2. The origin of this software must not be misrepresented, either
X *		by explicit claim or by omission.
X *
X *	3. Altered versions must be plainly marked as such, and must not
X *		be misrepresented as being the original software.
X *
X * Beware that some of this code is subtly aware of the way operator
X * precedence is structured in regular expressions.  Serious changes in
X * regular-expression syntax might require a total rethink.
X *
X */
X
X#include "env.h"
X
X#include <stdio.h>
X#include "regexp.h"
X#include "regmagic.h"
X
X/*
X * The "internal use only" fields in regexp.h are present to pass info from
X * compile to execute that permits the execute phase to run lots faster on
X * simple cases.  They are:
X *
X * regstart	char that must begin a match; '\0' if none obvious
X * reganch	is the match anchored (at beginning-of-line only)?
X * regmust	string (pointer into program) that match must include, or NULL
X * regmlen	length of regmust string
X *
X * Regstart and reganch permit very fast decisions on suitable starting points
X * for a match, cutting down the work a lot.  Regmust permits fast rejection
X * of lines that cannot possibly match.  The regmust tests are costly enough
X * that regcomp() supplies a regmust only if the r.e. contains something
X * potentially expensive (at present, the only such thing detected is * or +
X * at the start of the r.e., which can involve a lot of backup).  Regmlen is
X * supplied because the test in regexec() needs it and regcomp() is computing
X * it anyway.
X */
X
X/*
X * Structure for regexp "program".  This is essentially a linear encoding
X * of a nondeterministic finite-state machine (aka syntax charts or
X * "railroad normal form" in parsing technology).  Each node is an opcode
X * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
X * all nodes except BRANCH implement concatenation; a "next" pointer with
X * a BRANCH on both ends of it is connecting two alternatives.  (Here we
X * have one of the subtle syntax dependencies:  an individual BRANCH (as
X * opposed to a collection of them) is never concatenated with anything
X * because of operator precedence.)  The operand of some types of node is
X * a literal string; for others, it is a node leading into a sub-FSM.  In
X * particular, the operand of a BRANCH node is the first node of the branch.
X * (NB this is *not* a tree structure:  the tail of the branch connects
X * to the thing following the set of BRANCHes.)  The opcodes are:
X */
X
X/* definition	number	opnd?	meaning */
X#define	END	0	/* no	End of program. */
X#define	BOL	1	/* no	Match "" at beginning of line. */
X#define	EOL	2	/* no	Match "" at end of line. */
X#define	ANY	3	/* no	Match any one character. */
X#define	ANYOF	4	/* str	Match any character in this string. */
X#define	ANYBUT	5	/* str	Match any character not in this string. */
X#define	BRANCH	6	/* node	Match this alternative, or the next... */
X#define	BACK	7	/* no	Match "", "next" ptr points backward. */
X#define	EXACTLY	8	/* str	Match this string. */
X#define	NOTHING	9	/* no	Match empty string. */
X#define	STAR	10	/* node	Match this (simple) thing 0 or more times. */
X#define	PLUS	11	/* node	Match this (simple) thing 1 or more times. */
X#define	OPEN	20	/* no	Mark this point in input as start of #n. */
X			/*	OPEN+1 is number 1, etc. */
X#define	CLOSE	30	/* no	Analogous to OPEN. */
X
X/*
X * Opcode notes:
X *
X * BRANCH	The set of branches constituting a single choice are hooked
X *		together with their "next" pointers, since precedence prevents
X *		anything being concatenated to any individual branch.  The
X *		"next" pointer of the last BRANCH in a choice points to the
X *		thing following the whole choice.  This is also where the
X *		final "next" pointer of each individual branch points; each
X *		branch starts with the operand node of a BRANCH node.
X *
X * BACK		Normal "next" pointers all implicitly point forward; BACK
X *		exists to make loop structures possible.
X *
X * STAR,PLUS	'?', and complex '*' and '+', are implemented as circular
X *		BRANCH structures using BACK.  Simple cases (one character
X *		per match) are implemented with STAR and PLUS for speed
X *		and to minimize recursive plunges.
X *
X * OPEN,CLOSE	...are numbered at compile time.
X */
X
X/*
X * A node is one char of opcode followed by two chars of "next" pointer.
X * "Next" pointers are stored as two 8-bit pieces, high order first.  The
X * value is a positive offset from the opcode of the node containing it.
X * An operand, if any, simply follows the node.  (Note that much of the
X * code generation knows about this implicit relationship.)
X *
X * Using two bytes for the "next" pointer is vast overkill for most things,
X * but allows patterns to get big without disasters.
X */
X#define	OP(p)	(*(p))
X#define	NEXT(p)	(((*((p)+1)&0377)<<8) + (*((p)+2)&0377))
X#define	OPERAND(p)	((p) + 3)
X
X/*
X * See regmagic.h for one further detail of program structure.
X */
X
X
X/*
X * Utility definitions.
X */
X#ifndef CHARBITS
X#define	UCHARAT(p)	((int)*(unsigned char *)(p))
X#else
X#define	UCHARAT(p)	((int)*(p)&CHARBITS)
X#endif
X
X#define	FAIL(m)	{ regerror(m); return(NULL); }
X#define	ISMULT(c)	((c) == '*' || (c) == '+' || (c) == '?')
X#define	META	"^$.[()|?+*\\"
X
X/*
X * Flags to be passed up and down.
X */
X#define	HASWIDTH	01	/* Known never to match null string. */
X#define	SIMPLE		02	/* Simple enough to be STAR/PLUS operand. */
X#define	SPSTART		04	/* Starts with * or +. */
X#define	WORST		0	/* Worst case. */
X
X#ifndef	ORIGINAL
X/*
X * The following supports the ability to ignore case in searches.
X */
X
X#include <ctype.h>
X
Xint reg_ic = 0;			/* set by callers to ignore case */
X
X/*
X * mkup - convert to upper case IF we're doing caseless compares
X */
X#define	mkup(c)		((reg_ic && islower(c)) ? toupper(c) : (c))
X
X#endif
X
X/*
X * Global work variables for regcomp().
X */
Xstatic char *regparse;		/* Input-scan pointer. */
Xstatic int regnpar;		/* () count. */
Xstatic char regdummy;
Xstatic char *regcode;		/* Code-emit pointer; &regdummy = don't. */
Xstatic long regsize;		/* Code size. */
X
X/*
X * Forward declarations for regcomp()'s friends.
X */
X#ifndef STATIC
X#define	STATIC	static
X#endif
XSTATIC char *reg();
XSTATIC char *regbranch();
XSTATIC char *regpiece();
XSTATIC char *regatom();
XSTATIC char *regnode();
XSTATIC char *regnext();
XSTATIC void regc();
XSTATIC void reginsert();
XSTATIC void regtail();
XSTATIC void regoptail();
X#ifdef STRCSPN
XSTATIC int strcspn();
X#endif
X
X/*
X - regcomp - compile a regular expression into internal code
X *
X * We can't allocate space until we know how big the compiled form will be,
X * but we can't compile it (and thus know how big it is) until we've got a
X * place to put the code.  So we cheat:  we compile it twice, once with code
X * generation turned off and size counting turned on, and once "for real".
X * This also means that we don't allocate space until we are sure that the
X * thing really will compile successfully, and we never have to move the
X * code and thus invalidate pointers into it.  (Note that it has to be in
X * one piece because free() must be able to free it all.)
X *
X * Beware that the optimization-preparation code in here knows about some
X * of the structure of the compiled regexp.
X */
Xregexp *
Xregcomp(exp)
Xchar *exp;
X{
X	register regexp *r;
X	register char *scan;
X	register char *longest;
X	register int len;
X	int flags;
X	extern char *malloc();
X
X	if (exp == NULL)
X		FAIL("NULL argument");
X
X	/* First pass: determine size, legality. */
X	regparse = exp;
X	regnpar = 1;
X	regsize = 0L;
X	regcode = &regdummy;
X	regc(MAGIC);
X	if (reg(0, &flags) == NULL)
X		return(NULL);
X
X	/* Small enough for pointer-storage convention? */
X	if (regsize >= 32767L)		/* Probably could be 65535L. */
X		FAIL("regexp too big");
X
X	/* Allocate space. */
X	r = (regexp *)malloc(sizeof(regexp) + (unsigned)regsize);
X	if (r == NULL)
X		FAIL("out of space");
X
X	/* Second pass: emit code. */
X	regparse = exp;
X	regnpar = 1;
X	regcode = r->program;
X	regc(MAGIC);
X	if (reg(0, &flags) == NULL)
X		return(NULL);
X
X	/* Dig out information for optimizations. */
X	r->regstart = '\0';	/* Worst-case defaults. */
X	r->reganch = 0;
X	r->regmust = NULL;
X	r->regmlen = 0;
X	scan = r->program+1;			/* First BRANCH. */
X	if (OP(regnext(scan)) == END) {		/* Only one top-level choice. */
X		scan = OPERAND(scan);
X
X		/* Starting-point info. */
X		if (OP(scan) == EXACTLY)
X			r->regstart = *OPERAND(scan);
X		else if (OP(scan) == BOL)
X			r->reganch++;
X
X		/*
X		 * If there's something expensive in the r.e., find the
X		 * longest literal string that must appear and make it the
X		 * regmust.  Resolve ties in favor of later strings, since
X		 * the regstart check works with the beginning of the r.e.
X		 * and avoiding duplication strengthens checking.  Not a
X		 * strong reason, but sufficient in the absence of others.
X		 */
X		if (flags&SPSTART) {
X			longest = NULL;
X			len = 0;
X			for (; scan != NULL; scan = regnext(scan))
X				if (OP(scan) == EXACTLY && strlen(OPERAND(scan)) >= len) {
X					longest = OPERAND(scan);
X					len = strlen(OPERAND(scan));
X				}
X			r->regmust = longest;
X			r->regmlen = len;
X		}
X	}
X
X	return(r);
X}
X
X/*
X - reg - regular expression, i.e. main body or parenthesized thing
X *
X * Caller must absorb opening parenthesis.
X *
X * Combining parenthesis handling with the base level of regular expression
X * is a trifle forced, but the need to tie the tails of the branches to what
X * follows makes it hard to avoid.
X */
Xstatic char *
Xreg(paren, flagp)
Xint paren;			/* Parenthesized? */
Xint *flagp;
X{
X	register char *ret;
X	register char *br;
X	register char *ender;
X	register int parno;
X	int flags;
X
X	*flagp = HASWIDTH;	/* Tentatively. */
X
X	/* Make an OPEN node, if parenthesized. */
X	if (paren) {
X		if (regnpar >= NSUBEXP)
X			FAIL("too many ()");
X		parno = regnpar;
X		regnpar++;
X		ret = regnode(OPEN+parno);
X	} else
X		ret = NULL;
X
X	/* Pick up the branches, linking them together. */
X	br = regbranch(&flags);
X	if (br == NULL)
X		return(NULL);
X	if (ret != NULL)
X		regtail(ret, br);	/* OPEN -> first. */
X	else
X		ret = br;
X	if (!(flags&HASWIDTH))
X		*flagp &= ~HASWIDTH;
X	*flagp |= flags&SPSTART;
X	while (*regparse == '|') {
X		regparse++;
X		br = regbranch(&flags);
X		if (br == NULL)
X			return(NULL);
X		regtail(ret, br);	/* BRANCH -> BRANCH. */
X		if (!(flags&HASWIDTH))
X			*flagp &= ~HASWIDTH;
X		*flagp |= flags&SPSTART;
X	}
X
X	/* Make a closing node, and hook it on the end. */
X	ender = regnode((paren) ? CLOSE+parno : END);	
X	regtail(ret, ender);
X
X	/* Hook the tails of the branches to the closing node. */
X	for (br = ret; br != NULL; br = regnext(br))
X		regoptail(br, ender);
X
X	/* Check for proper termination. */
X	if (paren && *regparse++ != ')') {
X		FAIL("unmatched ()");
X	} else if (!paren && *regparse != '\0') {
X		if (*regparse == ')') {
X			FAIL("unmatched ()");
X		} else
X			FAIL("junk on end");	/* "Can't happen". */
X		/* NOTREACHED */
X	}
X
X	return(ret);
X}
X
X/*
X - regbranch - one alternative of an | operator
X *
X * Implements the concatenation operator.
X */
Xstatic char *
Xregbranch(flagp)
Xint *flagp;
X{
X	register char *ret;
X	register char *chain;
X	register char *latest;
X	int flags;
X
X	*flagp = WORST;		/* Tentatively. */
X
X	ret = regnode(BRANCH);
X	chain = NULL;
X	while (*regparse != '\0' && *regparse != '|' && *regparse != ')') {
X		latest = regpiece(&flags);
X		if (latest == NULL)
X			return(NULL);
X		*flagp |= flags&HASWIDTH;
X		if (chain == NULL)	/* First piece. */
X			*flagp |= flags&SPSTART;
X		else
X			regtail(chain, latest);
X		chain = latest;
X	}
X	if (chain == NULL)	/* Loop ran zero times. */
X		(void) regnode(NOTHING);
X
X	return(ret);
X}
X
X/*
X - regpiece - something followed by possible [*+?]
X *
X * Note that the branching code sequences used for ? and the general cases
X * of * and + are somewhat optimized:  they use the same NOTHING node as
X * both the endmarker for their branch list and the body of the last branch.
X * It might seem that this node could be dispensed with entirely, but the
X * endmarker role is not redundant.
X */
Xstatic char *
Xregpiece(flagp)
Xint *flagp;
X{
X	register char *ret;
X	register char op;
X	register char *next;
X	int flags;
X
X	ret = regatom(&flags);
X	if (ret == NULL)
X		return(NULL);
X
X	op = *regparse;
X	if (!ISMULT(op)) {
X		*flagp = flags;
X		return(ret);
X	}
X
X	if (!(flags&HASWIDTH) && op != '?')
X		FAIL("*+ operand could be empty");
X	*flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
X
X	if (op == '*' && (flags&SIMPLE))
X		reginsert(STAR, ret);
X	else if (op == '*') {
X		/* Emit x* as (x&|), where & means "self". */
X		reginsert(BRANCH, ret);			/* Either x */
X		regoptail(ret, regnode(BACK));		/* and loop */
X		regoptail(ret, ret);			/* back */
X		regtail(ret, regnode(BRANCH));		/* or */
X		regtail(ret, regnode(NOTHING));		/* null. */
X	} else if (op == '+' && (flags&SIMPLE))
X		reginsert(PLUS, ret);
X	else if (op == '+') {
X		/* Emit x+ as x(&|), where & means "self". */
X		next = regnode(BRANCH);			/* Either */
X		regtail(ret, next);
X		regtail(regnode(BACK), ret);		/* loop back */
X		regtail(next, regnode(BRANCH));		/* or */
X		regtail(ret, regnode(NOTHING));		/* null. */
X	} else if (op == '?') {
X		/* Emit x? as (x|) */
X		reginsert(BRANCH, ret);			/* Either x */
X		regtail(ret, regnode(BRANCH));		/* or */
X		next = regnode(NOTHING);		/* null. */
X		regtail(ret, next);
X		regoptail(ret, next);
X	}
X	regparse++;
X	if (ISMULT(*regparse))
X		FAIL("nested *?+");
X
X	return(ret);
X}
X
X/*
X - regatom - the lowest level
X *
X * Optimization:  gobbles an entire sequence of ordinary characters so that
X * it can turn them into a single node, which is smaller to store and
X * faster to run.  Backslashed characters are exceptions, each becoming a
X * separate node; the code is simpler that way and it's not worth fixing.
X */
Xstatic char *
Xregatom(flagp)
Xint *flagp;
X{
X	register char *ret;
X	int flags;
X
X	*flagp = WORST;		/* Tentatively. */
X
X	switch (*regparse++) {
X	case '^':
X		ret = regnode(BOL);
X		break;
X	case '$':
X		ret = regnode(EOL);
X		break;
X	case '.':
X		ret = regnode(ANY);
X		*flagp |= HASWIDTH|SIMPLE;
X		break;
X	case '[': {
X			register int class;
X			register int classend;
X
X			if (*regparse == '^') {	/* Complement of range. */
X				ret = regnode(ANYBUT);
X				regparse++;
X			} else
X				ret = regnode(ANYOF);
X			if (*regparse == ']' || *regparse == '-')
X				regc(*regparse++);
X			while (*regparse != '\0' && *regparse != ']') {
X				if (*regparse == '-') {
X					regparse++;
X					if (*regparse == ']' || *regparse == '\0')
X						regc('-');
X					else {
X						class = UCHARAT(regparse-2)+1;
X						classend = UCHARAT(regparse);
X						if (class > classend+1)
X							FAIL("invalid [] range");
X						for (; class <= classend; class++)
X							regc(class);
X						regparse++;
X					}
X				} else
X					regc(*regparse++);
X			}
X			regc('\0');
X			if (*regparse != ']')
X				FAIL("unmatched []");
X			regparse++;
X			*flagp |= HASWIDTH|SIMPLE;
X		}
X		break;
X	case '(':
X		ret = reg(1, &flags);
X		if (ret == NULL)
X			return(NULL);
X		*flagp |= flags&(HASWIDTH|SPSTART);
X		break;
X	case '\0':
X	case '|':
X	case ')':
X		FAIL("internal urp");	/* Supposed to be caught earlier. */
X		break;
X	case '?':
X	case '+':
X	case '*':
X		FAIL("?+* follows nothing");
X		break;
X	case '\\':
X		if (*regparse == '\0')
X			FAIL("trailing \\");
X		ret = regnode(EXACTLY);
X		regc(*regparse++);
X		regc('\0');
X		*flagp |= HASWIDTH|SIMPLE;
X		break;
X	default: {
X			register int len;
X			register char ender;
X
X			regparse--;
X			len = strcspn(regparse, META);
X			if (len <= 0)
X				FAIL("internal disaster");
X			ender = *(regparse+len);
X			if (len > 1 && ISMULT(ender))
X				len--;		/* Back off clear of ?+* operand. */
X			*flagp |= HASWIDTH;
X			if (len == 1)
X				*flagp |= SIMPLE;
X			ret = regnode(EXACTLY);
X			while (len > 0) {
X				regc(*regparse++);
X				len--;
X			}
X			regc('\0');
X		}
X		break;
X	}
X
X	return(ret);
X}
X
X/*
X - regnode - emit a node
X */
Xstatic char *			/* Location. */
Xregnode(op)
Xchar op;
X{
X	register char *ret;
X	register char *ptr;
X
X	ret = regcode;
X	if (ret == &regdummy) {
X		regsize += 3;
X		return(ret);
X	}
X
X	ptr = ret;
X	*ptr++ = op;
X	*ptr++ = '\0';		/* Null "next" pointer. */
X	*ptr++ = '\0';
X	regcode = ptr;
X
X	return(ret);
X}
X
X/*
X - regc - emit (if appropriate) a byte of code
X */
Xstatic void
Xregc(b)
Xchar b;
X{
X	if (regcode != &regdummy)
X		*regcode++ = b;
X	else
X		regsize++;
X}
X
X/*
X - reginsert - insert an operator in front of already-emitted operand
X *
X * Means relocating the operand.
X */
Xstatic void
Xreginsert(op, opnd)
Xchar op;
Xchar *opnd;
X{
X	register char *src;
X	register char *dst;
X	register char *place;
X
X	if (regcode == &regdummy) {
X		regsize += 3;
X		return;
X	}
X
X	src = regcode;
X	regcode += 3;
X	dst = regcode;
X	while (src > opnd)
X		*--dst = *--src;
X
X	place = opnd;		/* Op node, where operand used to be. */
X	*place++ = op;
X	*place++ = '\0';
X	*place++ = '\0';
X}
X
X/*
X - regtail - set the next-pointer at the end of a node chain
X */
Xstatic void
Xregtail(p, val)
Xchar *p;
Xchar *val;
X{
X	register char *scan;
X	register char *temp;
X	register int offset;
X
X	if (p == &regdummy)
X		return;
X
X	/* Find last node. */
X	scan = p;
X	for (;;) {
X		temp = regnext(scan);
X		if (temp == NULL)
X			break;
X		scan = temp;
X	}
X
X	if (OP(scan) == BACK)
X		offset = scan - val;
X	else
X		offset = val - scan;
X	*(scan+1) = (offset>>8)&0377;
X	*(scan+2) = offset&0377;
X}
X
X/*
X - regoptail - regtail on operand of first argument; nop if operandless
X */
Xstatic void
Xregoptail(p, val)
Xchar *p;
Xchar *val;
X{
X	/* "Operandless" and "op != BRANCH" are synonymous in practice. */
X	if (p == NULL || p == &regdummy || OP(p) != BRANCH)
X		return;
X	regtail(OPERAND(p), val);
X}
X
X/*
X * regexec and friends
X */
X
X/*
X * Global work variables for regexec().
X */
Xstatic char *reginput;		/* String-input pointer. */
Xstatic char *regbol;		/* Beginning of input, for ^ check. */
Xstatic char **regstartp;	/* Pointer to startp array. */
Xstatic char **regendp;		/* Ditto for endp. */
X
X/*
X * Forwards.
X */
XSTATIC int regtry();
XSTATIC int regmatch();
XSTATIC int regrepeat();
X
X#ifdef DEBUG
Xint regnarrate = 0;
Xvoid regdump();
XSTATIC char *regprop();
X#endif
X
X/*
X - regexec - match a regexp against a string
X */
Xint
Xregexec(prog, string, at_bol)
Xregister regexp *prog;
Xregister char *string;
Xint at_bol;
X{
X	register char *s;
X	extern char *cstrchr();
X
X	/* Be paranoid... */
X	if (prog == NULL || string == NULL) {
X		regerror("NULL parameter");
X		return(0);
X	}
X
X	/* Check validity of program. */
X	if (UCHARAT(prog->program) != MAGIC) {
X		regerror("corrupted program");
X		return(0);
X	}
X
X	/* If there is a "must appear" string, look for it. */
X	if (prog->regmust != NULL) {
X		s = string;
X		while ((s = cstrchr(s, prog->regmust[0])) != NULL) {
X			if (cstrncmp(s, prog->regmust, prog->regmlen) == 0)
X				break;	/* Found it. */
X			s++;
X		}
X		if (s == NULL)	/* Not present. */
X			return(0);
X	}
X
X	/* Mark beginning of line for ^ . */
X	if (at_bol)
X		regbol = string;	/* is possible to match bol */
X	else
X		regbol = NULL;		/* we aren't there, so don't match it */
X
X	/* Simplest case:  anchored match need be tried only once. */
X	if (prog->reganch)
X		return(regtry(prog, string));
X
X	/* Messy cases:  unanchored match. */
X	s = string;
X	if (prog->regstart != '\0')
X		/* We know what char it must start with. */
X		while ((s = cstrchr(s, prog->regstart)) != NULL) {
X			if (regtry(prog, s))
X				return(1);
X			s++;
X		}
X	else
X		/* We don't -- general case. */
X		do {
X			if (regtry(prog, s))
X				return(1);
X		} while (*s++ != '\0');
X
X	/* Failure. */
X	return(0);
X}
X
X/*
X - regtry - try match at specific point
X */
Xstatic int			/* 0 failure, 1 success */
Xregtry(prog, string)
Xregexp *prog;
Xchar *string;
X{
X	register int i;
X	register char **sp;
X	register char **ep;
X
X	reginput = string;
X	regstartp = prog->startp;
X	regendp = prog->endp;
X
X	sp = prog->startp;
X	ep = prog->endp;
X	for (i = NSUBEXP; i > 0; i--) {
X		*sp++ = NULL;
X		*ep++ = NULL;
X	}
X	if (regmatch(prog->program + 1)) {
X		prog->startp[0] = string;
X		prog->endp[0] = reginput;
X		return(1);
X	} else
X		return(0);
X}
X
X/*
X - regmatch - main matching routine
X *
X * Conceptually the strategy is simple:  check to see whether the current
X * node matches, call self recursively to see whether the rest matches,
X * and then act accordingly.  In practice we make some effort to avoid
X * recursion, in particular by going through "ordinary" nodes (that don't
X * need to know whether the rest of the match failed) by a loop instead of
X * by recursion.
X */
Xstatic int			/* 0 failure, 1 success */
Xregmatch(prog)
Xchar *prog;
X{
X	register char *scan;	/* Current node. */
X	char *next;		/* Next node. */
X	extern char *strchr();
X
X	scan = prog;
X#ifdef DEBUG
X	if (scan != NULL && regnarrate)
X		fprintf(stderr, "%s(\n", regprop(scan));
X#endif
X	while (scan != NULL) {
X#ifdef DEBUG
X		if (regnarrate)
X			fprintf(stderr, "%s...\n", regprop(scan));
X#endif
X		next = regnext(scan);
X
X		switch (OP(scan)) {
X		case BOL:
X			if (reginput != regbol)
X				return(0);
X			break;
X		case EOL:
X			if (*reginput != '\0')
X				return(0);
X			break;
X		case ANY:
X			if (*reginput == '\0')
X				return(0);
X			reginput++;
X			break;
X		case EXACTLY: {
X				register int len;
X				register char *opnd;
X
X				opnd = OPERAND(scan);
X				/* Inline the first character, for speed. */
X				if (mkup(*opnd) != mkup(*reginput))
X					return(0);
X				len = strlen(opnd);
X				if (len > 1 && cstrncmp(opnd,reginput,len) != 0)
X					return(0);
X				reginput += len;
X			}
X			break;
X		case ANYOF:
X 			if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) == NULL)
X				return(0);
X			reginput++;
X			break;
X		case ANYBUT:
X 			if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) != NULL)
X				return(0);
X			reginput++;
X			break;
X		case NOTHING:
X			break;
X		case BACK:
X			break;
X		case OPEN+1:
X		case OPEN+2:
X		case OPEN+3:
X		case OPEN+4:
X		case OPEN+5:
X		case OPEN+6:
X		case OPEN+7:
X		case OPEN+8:
X		case OPEN+9: {
X				register int no;
X				register char *save;
X
X				no = OP(scan) - OPEN;
X				save = reginput;
X
X				if (regmatch(next)) {
X					/*
X					 * Don't set startp if some later
X					 * invocation of the same parentheses
X					 * already has.
X					 */
X					if (regstartp[no] == NULL)
X						regstartp[no] = save;
X					return(1);
X				} else
X					return(0);
X			}
X			break;
X		case CLOSE+1:
X		case CLOSE+2:
X		case CLOSE+3:
X		case CLOSE+4:
X		case CLOSE+5:
X		case CLOSE+6:
X		case CLOSE+7:
X		case CLOSE+8:
X		case CLOSE+9: {
X				register int no;
X				register char *save;
X
X				no = OP(scan) - CLOSE;
X				save = reginput;
X
X				if (regmatch(next)) {
X					/*
X					 * Don't set endp if some later
X					 * invocation of the same parentheses
X					 * already has.
X					 */
X					if (regendp[no] == NULL)
X						regendp[no] = save;
X					return(1);
X				} else
X					return(0);
X			}
X			break;
X		case BRANCH: {
X				register char *save;
X
X				if (OP(next) != BRANCH)		/* No choice. */
X					next = OPERAND(scan);	/* Avoid recursion. */
X				else {
X					do {
X						save = reginput;
X						if (regmatch(OPERAND(scan)))
X							return(1);
X						reginput = save;
X						scan = regnext(scan);
X					} while (scan != NULL && OP(scan) == BRANCH);
X					return(0);
X					/* NOTREACHED */
X				}
X			}
X			break;
X		case STAR:
X		case PLUS: {
X				register char nextch;
X				register int no;
X				register char *save;
X				register int min;
X
X				/*
X				 * Lookahead to avoid useless match attempts
X				 * when we know what character comes next.
X				 */
X				nextch = '\0';
X				if (OP(next) == EXACTLY)
X					nextch = *OPERAND(next);
X				min = (OP(scan) == STAR) ? 0 : 1;
X				save = reginput;
X				no = regrepeat(OPERAND(scan));
X				while (no >= min) {
X					/* If it could work, try it. */
X					if (nextch == '\0' || *reginput == nextch)
X						if (regmatch(next))
X							return(1);
X					/* Couldn't or didn't -- back up. */
X					no--;
X					reginput = save + no;
X				}
X				return(0);
X			}
X			break;
X		case END:
X			return(1);	/* Success! */
X			break;
X		default:
X			regerror("memory corruption");
X			return(0);
X			break;
X		}
X
X		scan = next;
X	}
X
X	/*
X	 * We get here only if there's trouble -- normally "case END" is
X	 * the terminating point.
X	 */
X	regerror("corrupted pointers");
X	return(0);
X}
X
X/*
X - regrepeat - repeatedly match something simple, report how many
X */
Xstatic int
Xregrepeat(p)
Xchar *p;
X{
X	register int count = 0;
X	register char *scan;
X	register char *opnd;
X
X	scan = reginput;
X	opnd = OPERAND(p);
X	switch (OP(p)) {
X	case ANY:
X		count = strlen(scan);
X		scan += count;
X		break;
X	case EXACTLY:
X		while (mkup(*opnd) == mkup(*scan)) {
X			count++;
X			scan++;
X		}
X		break;
X	case ANYOF:
X		while (*scan != '\0' && strchr(opnd, *scan) != NULL) {
X			count++;
X			scan++;
X		}
X		break;
X	case ANYBUT:
X		while (*scan != '\0' && strchr(opnd, *scan) == NULL) {
X			count++;
X			scan++;
X		}
X		break;
X	default:		/* Oh dear.  Called inappropriately. */
X		regerror("internal foulup");
X		count = 0;	/* Best compromise. */
X		break;
X	}
X	reginput = scan;
X
X	return(count);
X}
X
X/*
X - regnext - dig the "next" pointer out of a node
X */
Xstatic char *
Xregnext(p)
Xregister char *p;
X{
X	register int offset;
X
X	if (p == &regdummy)
X		return(NULL);
X
X	offset = NEXT(p);
X	if (offset == 0)
X		return(NULL);
X
X	if (OP(p) == BACK)
X		return(p-offset);
X	else
X		return(p+offset);
X}
X
X#ifdef DEBUG
X
XSTATIC char *regprop();
X
X/*
X - regdump - dump a regexp onto stdout in vaguely comprehensible form
X */
Xvoid
Xregdump(r)
Xregexp *r;
X{
X	register char *s;
X	register char op = EXACTLY;	/* Arbitrary non-END op. */
X	register char *next;
X	extern char *strchr();
X
X
X	s = r->program + 1;
X	while (op != END) {	/* While that wasn't END last time... */
X		op = OP(s);
X		printf("%2d%s", s-r->program, regprop(s));	/* Where, what. */
X		next = regnext(s);
X		if (next == NULL)		/* Next ptr. */
X			printf("(0)");
X		else 
X			printf("(%d)", (s-r->program)+(next-s));
X		s += 3;
X		if (op == ANYOF || op == ANYBUT || op == EXACTLY) {
X			/* Literal string, where present. */
X			while (*s != '\0') {
X				putchar(*s);
X				s++;
X			}
X			s++;
X		}
X		putchar('\n');
X	}
X
X	/* Header fields of interest. */
X	if (r->regstart != '\0')
X		printf("start `%c' ", r->regstart);
X	if (r->reganch)
X		printf("anchored ");
X	if (r->regmust != NULL)
X		printf("must have \"%s\"", r->regmust);
X	printf("\n");
X}
X
X/*
X - regprop - printable representation of opcode
X */
Xstatic char *
Xregprop(op)
Xchar *op;
X{
X	register char *p;
X	static char buf[50];
X
X	(void) strcpy(buf, ":");
X
X	switch (OP(op)) {
X	case BOL:
X		p = "BOL";
X		break;
X	case EOL:
X		p = "EOL";
X		break;
X	case ANY:
X		p = "ANY";
X		break;
X	case ANYOF:
X		p = "ANYOF";
X		break;
X	case ANYBUT:
X		p = "ANYBUT";
X		break;
X	case BRANCH:
X		p = "BRANCH";
X		break;
X	case EXACTLY:
X		p = "EXACTLY";
X		break;
X	case NOTHING:
X		p = "NOTHING";
X		break;
X	case BACK:
X		p = "BACK";
X		break;
X	case END:
X		p = "END";
X		break;
X	case OPEN+1:
X	case OPEN+2:
X	case OPEN+3:
X	case OPEN+4:
X	case OPEN+5:
X	case OPEN+6:
X	case OPEN+7:
X	case OPEN+8:
X	case OPEN+9:
X		sprintf(buf+strlen(buf), "OPEN%d", OP(op)-OPEN);
X		p = NULL;
X		break;
X	case CLOSE+1:
X	case CLOSE+2:
X	case CLOSE+3:
X	case CLOSE+4:
X	case CLOSE+5:
X	case CLOSE+6:
X	case CLOSE+7:
X	case CLOSE+8:
X	case CLOSE+9:
X		sprintf(buf+strlen(buf), "CLOSE%d", OP(op)-CLOSE);
X		p = NULL;
X		break;
X	case STAR:
X		p = "STAR";
X		break;
X	case PLUS:
X		p = "PLUS";
X		break;
X	default:
X		regerror("corrupted opcode");
X		break;
X	}
X	if (p != NULL)
X		(void) strcat(buf, p);
X	return(buf);
X}
X#endif
X
X/*
X * The following is provided for those people who do not have strcspn() in
X * their C libraries.  They should get off their butts and do something
X * about it; at least one public-domain implementation of those (highly
X * useful) string routines has been published on Usenet.
X */
X#ifdef STRCSPN
X/*
X * strcspn - find length of initial segment of s1 consisting entirely
X * of characters not from s2
X */
X
Xstatic int
Xstrcspn(s1, s2)
Xchar *s1;
Xchar *s2;
X{
X	register char *scan1;
X	register char *scan2;
X	register int count;
X
X	count = 0;
X	for (scan1 = s1; *scan1 != '\0'; scan1++) {
X		for (scan2 = s2; *scan2 != '\0';)	/* ++ moved down. */
X			if (*scan1 == *scan2++)
X				return(count);
X		count++;
X	}
X	return(count);
X}
X#endif
X
Xint
Xcstrncmp(s1, s2, n)
Xchar	*s1, *s2;
Xint	n;
X{
X	char	*p, *S1, *S2, *strsave();
X	int	rval;
X
X	if (!reg_ic)
X		return (strncmp(s1, s2, n));
X
X	S1 = strsave(s1);
X	S2 = strsave(s2);
X
X	for (p = S1; *p ;p++)
X		if (islower(*p))
X			*p = toupper(*p);
X
X	for (p = S2; *p ;p++)
X		if (islower(*p))
X			*p = toupper(*p);
X
X	rval = strncmp(S1, S2, n);
X
X	free(S1);
X	free(S2);
X
X	return rval;
X}
X
Xchar *
Xcstrchr(s, c)
Xchar	*s;
Xchar	c;
X{
X	char	*p;
X
X	for (p = s; *p ;p++) {
X		if (mkup(*p) == mkup(c))
X			return p;
X	}
X	return NULL;
X}
!EOR!
echo extracting - regsub.c
sed 's/^X//' > regsub.c << '!EOR!'
X/* $Header: /nw/tony/src/stevie/src/RCS/regsub.c,v 1.4 89/03/11 22:43:30 tony Exp $
X *
X * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
X *
X * This is NOT the original regular expression code as written by
X * Henry Spencer. This code has been modified specifically for use
X * with the STEVIE editor, and should not be used apart from compiling
X * STEVIE. If you want a good regular expression library, get the
X * original code. The copyright notice that follows is from the
X * original.
X *
X * NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE
X *
X * regsub
X *
X *	Copyright (c) 1986 by University of Toronto.
X *	Written by Henry Spencer.  Not derived from licensed software.
X *
X *	Permission is granted to anyone to use this software for any
X *	purpose on any computer system, and to redistribute it freely,
X *	subject to the following restrictions:
X *
X *	1. The author is not responsible for the consequences of use of
X *		this software, no matter how awful, even if they arise
X *		from defects in it.
X *
X *	2. The origin of this software must not be misrepresented, either
X *		by explicit claim or by omission.
X *
X *	3. Altered versions must be plainly marked as such, and must not
X *		be misrepresented as being the original software.
X *
X */
X
X#include <stdio.h>
X#include "regexp.h"
X#include "regmagic.h"
X
X#ifndef CHARBITS
X#define	UCHARAT(p)	((int)*(unsigned char *)(p))
X#else
X#define	UCHARAT(p)	((int)*(p)&CHARBITS)
X#endif
X
X/*
X - regsub - perform substitutions after a regexp match
X */
Xvoid
Xregsub(prog, source, dest)
Xregexp *prog;
Xchar *source;
Xchar *dest;
X{
X	register char *src;
X	register char *dst;
X	register char c;
X	register int no;
X	register int len;
X	extern char *strncpy();
X
X	if (prog == NULL || source == NULL || dest == NULL) {
X		regerror("NULL parm to regsub");
X		return;
X	}
X	if (UCHARAT(prog->program) != MAGIC) {
X		regerror("damaged regexp fed to regsub");
X		return;
X	}
X
X	src = source;
X	dst = dest;
X	while ((c = *src++) != '\0') {
X		if (c == '&')
X			no = 0;
X		else if (c == '\\' && '0' <= *src && *src <= '9')
X			no = *src++ - '0';
X		else
X			no = -1;
X 		if (no < 0) {	/* Ordinary character. */
X 			if (c == '\\' && (*src == '\\' || *src == '&'))
X 				c = *src++;
X 			*dst++ = c;
X 		} else if (prog->startp[no] != NULL && prog->endp[no] != NULL) {
X			len = prog->endp[no] - prog->startp[no];
X			(void) strncpy(dst, prog->startp[no], len);
X			dst += len;
X			if (len != 0 && *(dst-1) == '\0') {	/* strncpy hit NUL. */
X				regerror("damaged match string");
X				return;
X			}
X		}
X	}
X	*dst++ = '\0';
X}
!EOR!
echo extracting - screen.c
sed 's/^X//' > screen.c << '!EOR!'
X/* $Header: /nw/tony/src/stevie/src/RCS/screen.c,v 1.8 89/08/02 09:26:33 tony Exp $
X *
X * Routines to manipulate the screen representations.
X */
X
X#include "stevie.h"
X
X/*
X * This gets set if we ignored an update request while input was pending.
X * We check this when the input is drained to see if the screen should be
X * updated.
X */
Xbool_t	need_redraw = FALSE;
X
X/*
X * The following variable is set (in filetonext) to the number of physical
X * lines taken by the line the cursor is on. We use this to avoid extra
X * calls to plines(). The optimized routines lfiletonext() and lnexttoscreen()
X * make sure that the size of the cursor line hasn't changed. If so, lines
X * below the cursor will move up or down and we need to call the routines
X * filetonext() and nexttoscreen() to examine the entire screen.
X */
Xstatic	int	Cline_size;	/* size (in rows) of the cursor line */
Xstatic	int	Cline_row;	/* starting row of the cursor line */
X
Xstatic	char	*mkline();	/* calculate line string for "number" mode */
X
X/*
X * filetonext()
X *
X * Based on the current value of Topchar, transfer a screenfull of
X * stuff from Filemem to Nextscreen, and update Botchar.
X */
X
Xstatic void
Xfiletonext()
X{
X	register int	row, col;
X	register char	*screenp = Nextscreen;
X	LPTR	memp;
X	LPTR	save;			/* save pos. in case line won't fit */
X	register char	*endscreen;
X	register char	*nextrow;
X	char	extra[16];
X	int	nextra = 0;
X	register int	c;
X	int	n;
X	bool_t	done;		/* if TRUE, we hit the end of the file */
X	bool_t	didline;	/* if TRUE, we finished the last line */
X	int	srow;		/* starting row of the current line */
X	int	lno;		/* number of the line we're doing */
X	int	coff;		/* column offset */
X
X	coff = P(P_NU) ? 8 : 0;
X
X	save = memp = *Topchar;
X
X	if (P(P_NU))
X		lno = cntllines(Filemem, Topchar);
X
X	/*
X	 * The number of rows shown is Rows-1.
X	 * The last line is the status/command line.
X	 */
X	endscreen = &screenp[(Rows-1)*Columns];
X
X	done = didline = FALSE;
X	srow = row = col = 0;
X	/*
X	 * We go one past the end of the screen so we can find out if the
X	 * last line fit on the screen or not.
X	 */
X	while ( screenp <= endscreen && !done) {
X
X
X		if (P(P_NU) && col == 0 && memp.index == 0) {
X			strcpy(extra, mkline(lno++));
X			nextra = 8;
X		}
X
X		/* Get the next character to put on the screen. */
X
X		/* The 'extra' array contains the extra stuff that is */
X		/* inserted to represent special characters (tabs, and */
X		/* other non-printable stuff.  The order in the 'extra' */
X		/* array is reversed. */
X
X		if ( nextra > 0 )
X			c = extra[--nextra];
X		else {
X			c = (unsigned)(0xff & gchar(&memp));
X			if (inc(&memp) == -1)
X				done = 1;
X			/* when getting a character from the file, we */
X			/* may have to turn it into something else on */
X			/* the way to putting it into 'Nextscreen'. */
X			if ( c == TAB && !P(P_LS) ) {
X				strcpy(extra,"        ");
X				/* tab amount depends on current column */
X				nextra = ((P(P_TS)-1) - (col - coff)%P(P_TS));
X				c = ' ';
X			}
X			else if ( c == NUL && P(P_LS) ) {
X				extra[0] = NUL;
X				nextra = 1;
X				c = '$';
X			} else if ( (n = chars[c].ch_size) > 1 ) {
X				char *p;
X				nextra = 0;
X				p = chars[c].ch_str;
X				/* copy 'ch-str'ing into 'extra' in reverse */
X				while ( n > 1 )
X					extra[nextra++] = p[--n];
X				c = p[0];
X			}
X		}
X
X		if (screenp == endscreen) {
X			/*
X			 * We're one past the end of the screen. If the
X			 * current character is null, then we really did
X			 * finish, so set didline = TRUE. In either case,
X			 * break out because we're done.
X			 */
X			dec(&memp);
X			if (memp.index != 0 && c == NUL) {
X				didline = TRUE;
X				inc(&memp);
X			}
X			break;
X		}
X
X		if ( c == NUL ) {
X			srow = ++row;
X			/*
X			 * Save this position in case the next line won't
X			 * fit on the screen completely.
X			 */
X			save = memp;
X			/* get pointer to start of next row */
X			nextrow = &Nextscreen[row*Columns];
X			/* blank out the rest of this row */
X			while ( screenp != nextrow )
X				*screenp++ = ' ';
X			col = 0;
X			continue;
X		}
X		if ( col >= Columns ) {
X			row++;
X			col = 0;
X		}
X		/* store the character in Nextscreen */
X		*screenp++ = c;
X		col++;
X	}
X	/*
X	 * If we didn't hit the end of the file, and we didn't finish
X	 * the last line we were working on, then the line didn't fit.
X	 */
X	if (!done && !didline) {
X		/*
X		 * Clear the rest of the screen and mark the unused lines.
X		 */
X		screenp = &Nextscreen[srow * Columns];
X		while (screenp < endscreen)
X			*screenp++ = ' ';
X		for (; srow < (Rows-1) ;srow++)
X			Nextscreen[srow * Columns] = '@';
X		*Botchar = save;
X		return;
X	}
X	/* make sure the rest of the screen is blank */
X	while ( screenp < endscreen )
X		*screenp++ = ' ';
X	/* put '~'s on rows that aren't part of the file. */
X	if ( col != 0 )
X		row++;
X	while ( row < Rows ) {
X		Nextscreen[row*Columns] = '~';
X		row++;
X	}
X	if (done)	/* we hit the end of the file */
X		*Botchar = *Fileend;
X	else
X		*Botchar = memp;	/* FIX - prev? */
X}
X
X/*
X * nexttoscreen
X *
X * Transfer the contents of Nextscreen to the screen, using Realscreen
X * to avoid unnecessary output.
X */
Xstatic void
Xnexttoscreen()
X{
X	register char	*np = Nextscreen;
X	register char	*rp = Realscreen;
X	register char	*endscreen;
X	register int	row = 0, col = 0;
X	int	gorow = -1, gocol = -1;
X
X	if (anyinput()) {
X		need_redraw = TRUE;
X		return;
X	}
X
X	endscreen = &np[(Rows-1)*Columns];
X
X	CUROFF;		/* disable cursor */
X
X	for ( ; np < endscreen ; np++,rp++ ) {
X		/* If desired screen (contents of Nextscreen) does not */
X		/* match what's really there, put it there. */
X		if ( *np != *rp ) {
X			/* if we are positioned at the right place, */
X			/* we don't have to use windgoto(). */
X			if (gocol != col || gorow != row) {
X				/*
X				 * If we're just off by one, don't send
X				 * an entire esc. seq. (this happens a lot!)
X				 */
X				if (gorow == row && gocol+1 == col) {
X					outchar(*(np-1));
X					gocol++;
X				} else
X					windgoto(gorow=row,gocol=col);
X			}
X			outchar(*rp = *np);
X			gocol++;
X		}
X		if ( ++col >= Columns ) {
X			col = 0;
X			row++;
X		}
X	}
X	CURON;		/* enable cursor again */
X}
X
X/*
X * lfiletonext() - like filetonext() but only for cursor line
X *
X * Returns true if the size of the cursor line (in rows) hasn't changed.
X * This determines whether or not we need to call filetonext() to examine
X * the entire screen for changes.
X */
Xstatic bool_t
Xlfiletonext()
X{
X	register int	row, col;
X	register char	*screenp;
X	LPTR	memp;
X	register char	*nextrow;
X	char	extra[16];
X	int	nextra = 0;
X	register int	c;
X	int	n;
X	bool_t	eof;
X	int	lno;		/* number of the line we're doing */
X	int	coff;		/* column offset */
X
X	coff = P(P_NU) ? 8 : 0;
X
X	/*
X	 * This should be done more efficiently.
X	 */
X	if (P(P_NU))
X		lno = cntllines(Filemem, Curschar);
X
X	screenp = Nextscreen + (Cline_row * Columns);
X
X	memp = *Curschar;
X	memp.index = 0;
X
X	eof = FALSE;
X	col = 0;
X	row = Cline_row;
X
X	while (!eof) {
X
X		if (P(P_NU) && col == 0 && memp.index == 0) {
X			strcpy(extra, mkline(lno));
X			nextra = 8;
X		}
X
X		/* Get the next character to put on the screen. */
X
X		/* The 'extra' array contains the extra stuff that is */
X		/* inserted to represent special characters (tabs, and */
X		/* other non-printable stuff.  The order in the 'extra' */
X		/* array is reversed. */
X
X		if ( nextra > 0 )
X			c = extra[--nextra];
X		else {
X			c = (unsigned)(0xff & gchar(&memp));
X			if (inc(&memp) == -1)
X				eof = TRUE;
X			/* when getting a character from the file, we */
X			/* may have to turn it into something else on */
X			/* the way to putting it into 'Nextscreen'. */
X			if ( c == TAB && !P(P_LS) ) {
X				strcpy(extra,"        ");
X				/* tab amount depends on current column */
X				nextra = ((P(P_TS)-1) - (col - coff)%P(P_TS));
X				c = ' ';
X			} else if ( c == NUL && P(P_LS) ) {
X				extra[0] = NUL;
X				nextra = 1;
X				c = '$';
X			} else if ( c != NUL && (n=chars[c].ch_size) > 1 ) {
X				char *p;
X				nextra = 0;
X				p = chars[c].ch_str;
X				/* copy 'ch-str'ing into 'extra' in reverse */
X				while ( n > 1 )
X					extra[nextra++] = p[--n];
X				c = p[0];
X			}
X		}
X
X		if ( c == NUL ) {
X			row++;
X			/* get pointer to start of next row */
X			nextrow = &Nextscreen[row*Columns];
X			/* blank out the rest of this row */
X			while ( screenp != nextrow )
X				*screenp++ = ' ';
X			col = 0;
X			break;
X		}
X
X		if ( col >= Columns ) {
X			row++;
X			col = 0;
X		}
X		/* store the character in Nextscreen */
X		*screenp++ = c;
X		col++;
X	}
X	return ((row - Cline_row) == Cline_size);
X}
X
X/*
X * lnexttoscreen
X *
X * Like nexttoscreen() but only for the cursor line.
X */
Xstatic void
Xlnexttoscreen()
X{
X	register char	*np = Nextscreen + (Cline_row * Columns);
X	register char	*rp = Realscreen + (Cline_row * Columns);
X	register char	*endline;
X	register int	row, col;
X	int	gorow = -1, gocol = -1;
X
X	if (anyinput()) {
X		need_redraw = TRUE;
X		return;
X	}
X
X	endline = np + (Cline_size * Columns);
X
X	row = Cline_row;
X	col = 0;
X
X	CUROFF;		/* disable cursor */
X
X	for ( ; np < endline ; np++,rp++ ) {
X		/* If desired screen (contents of Nextscreen) does not */
X		/* match what's really there, put it there. */
X		if ( *np != *rp ) {
X			/* if we are positioned at the right place, */
X			/* we don't have to use windgoto(). */
X			if (gocol != col || gorow != row) {
X				/*
X				 * If we're just off by one, don't send
X				 * an entire esc. seq. (this happens a lot!)
X				 */
X				if (gorow == row && gocol+1 == col) {
X					outchar(*(np-1));
X					gocol++;
X				} else
X					windgoto(gorow=row,gocol=col);
X			}
X			outchar(*rp = *np);
X			gocol++;
X		}
X		if ( ++col >= Columns ) {
X			col = 0;
X			row++;
X		}
X	}
X	CURON;		/* enable cursor again */
X}
X
Xstatic char *
Xmkline(n)
Xregister int	n;
X{
X	static	char	lbuf[9];
X	register int	i = 2;
X
X	strcpy(lbuf, "        ");
X
X	lbuf[i++] = (n % 10) + '0';
X	n /= 10;
X	if (n != 0) {
X		lbuf[i++] = (n % 10) + '0';
X		n /= 10;
X	}
X	if (n != 0) {
X		lbuf[i++] = (n % 10) + '0';
X		n /= 10;
X	}
X	if (n != 0) {
X		lbuf[i++] = (n % 10) + '0';
X		n /= 10;
X	}
X	if (n != 0) {
X		lbuf[i++] = (n % 10) + '0';
X		n /= 10;
X	}
X	return lbuf;
X}
X
X/*
X * updateline() - update the line the cursor is on
X *
X * Updateline() is called after changes that only affect the line that
X * the cursor is on. This improves performance tremendously for normal
X * insert mode operation. The only thing we have to watch for is when
X * the cursor line grows or shrinks around a row boundary. This means
X * we have to repaint other parts of the screen appropriately. If
X * lfiletonext() returns FALSE, the size of the cursor line (in rows)
X * has changed and we have to call updatescreen() to do a complete job.
X */
Xvoid
Xupdateline()
X{
X	if (!lfiletonext())
X		updatescreen();	/* bag it, do the whole screen */
X	else
X		lnexttoscreen();
X}
X
Xvoid
Xupdatescreen()
X{
X	extern	bool_t	interactive;
X
X	if (interactive) {
X		filetonext();
X		nexttoscreen();
X	}
X}
X
X/*
X * prt_line() - print the given line
X */
Xvoid
Xprt_line(s)
Xchar	*s;
X{
X	register int	si = 0;
X	register int	c;
X	register int	col = 0;
X
X	char	extra[16];
X	int	nextra = 0;
X	int	n;
X
X	for (;;) {
X
X		if ( nextra > 0 )
X			c = extra[--nextra];
X		else {
X			c = s[si++];
X			if ( c == TAB && !P(P_LS) ) {
X				strcpy(extra, "        ");
X				/* tab amount depends on current column */
X				nextra = (P(P_TS) - 1) - col%P(P_TS);
X				c = ' ';
X			} else if ( c == NUL && P(P_LS) ) {
X				extra[0] = NUL;
X				nextra = 1;
X				c = '$';
X			} else if ( c != NUL && (n=chars[c].ch_size) > 1 ) {
X				char	*p;
X
X				nextra = 0;
X				p = chars[c].ch_str;
X				/* copy 'ch-str'ing into 'extra' in reverse */
X				while ( n > 1 )
X					extra[nextra++] = p[--n];
X				c = p[0];
X			}
X		}
X
X		if ( c == NUL )
X			break;
X
X		outchar(c);
X		col++;
X	}
X}
X
Xvoid
Xscreenclear()
X{
X	register char	*rp, *np;
X	register char	*end;
X
X	CLS;		/* clear the display */
X
X	rp  = Realscreen;
X	end = Realscreen + Rows * Columns;
X	np  = Nextscreen;
X
X	/* blank out the stored screens */
X	while (rp != end)
X		*rp++ = *np++ = ' ';
X}
X
Xvoid
Xcursupdate()
X{
X	register LPTR	*p;
X	register int	icnt, c, nlines;
X	register int	i;
X	int	didinc;
X
X	if (bufempty()) {		/* special case - file is empty */
X		*Topchar  = *Filemem;
X		*Curschar = *Filemem;
X	} else if ( LINEOF(Curschar) < LINEOF(Topchar) ) {
X		nlines = cntllines(Curschar,Topchar);
X		/* if the cursor is above the top of */
X		/* the screen, put it at the top of the screen.. */
X		*Topchar = *Curschar;
X		Topchar->index = 0;
X		/* ... and, if we weren't very close to begin with, */
X		/* we scroll so that the line is close to the middle. */
X		if ( nlines > Rows/3 ) {
X			for (i=0, p = Topchar; i < Rows/3 ;i++, *Topchar = *p)
X				if ((p = prevline(p)) == NULL)
X					break;
X		} else
X			s_ins(0, nlines-1);
X		updatescreen();
X	}
X	else if (LINEOF(Curschar) >= LINEOF(Botchar)) {
X		nlines = cntllines(Botchar,Curschar);
X		/* If the cursor is off the bottom of the screen, */
X		/* put it at the top of the screen.. */
X		/* ... and back up */
X		if ( nlines > Rows/3 ) {
X			p = Curschar;
X			for (i=0; i < (2*Rows)/3 ;i++)
X				if ((p = prevline(p)) == NULL)
X					break;
X			*Topchar = *p;
X		} else {
X			scrollup(nlines);
X		}
X		updatescreen();
X	}
X
X	Cursrow = Curscol = Cursvcol = 0;
X	for ( p=Topchar; p->linep != Curschar->linep ;p = nextline(p) )
X		Cursrow += plines(p);
X
X	Cline_row = Cursrow;
X	Cline_size = plines(p);
X
X	if (P(P_NU))
X		Curscol = 8;
X
X	for (i=0; i <= Curschar->index ;i++) {
X		c = Curschar->linep->s[i];
X		/* A tab gets expanded, depending on the current column */
X		if ( c == TAB && !P(P_LS) )
X			icnt = P(P_TS) - (Cursvcol % P(P_TS));
X		else
X			icnt = chars[(unsigned)(c & 0xff)].ch_size;
X		Curscol += icnt;
X		Cursvcol += icnt;
X		if ( Curscol >= Columns ) {
X			Curscol -= Columns;
X			Cursrow++;
X			didinc = TRUE;
X		}
X		else
X			didinc = FALSE;
X	}
X	if (didinc)
X		Cursrow--;
X
X	if (c == TAB && State == NORMAL && !P(P_LS)) {
X		Curscol--;
X		Cursvcol--;
X	} else {
X		Curscol -= icnt;
X		Cursvcol -= icnt;
X	}
X	if (Curscol < 0)
X		Curscol += Columns;
X
X	if (set_want_col) {
X		Curswant = Cursvcol;
X		set_want_col = FALSE;
X	}
X}
X
X/*
X * The rest of the routines in this file perform screen manipulations.
X * The given operation is performed physically on the screen. The
X * corresponding change is also made to the internal screen image.
X * In this way, the editor anticipates the effect of editing changes
X * on the appearance of the screen. That way, when we call screenupdate
X * a complete redraw isn't usually necessary. Another advantage is that
X * we can keep adding code to anticipate screen changes, and in the
X * meantime, everything still works.
X */
X
X/*
X * s_ins(row, nlines) - insert 'nlines' lines at 'row'
X */
Xvoid
Xs_ins(row, nlines)
Xint	row;
Xint	nlines;
X{
X	register char	*s, *d;		/* src & dest for block copy */
X	register char	*e;		/* end point for copy */
X	register int	i;
X
X	if ( ! CANIL )		/* can't do it */
X		return;
X
X	/*
X	 * It "looks" better if we do all the inserts at once
X	 */
X	SAVCUR;			/* save position */
X	windgoto(row, 0);
X
X	CRTIL( row, nlines );
X
X	windgoto(Rows-1, 0);	/* delete any garbage that may have */
X	CLEOL;			/* been shifted to the bottom line */
X	RESCUR;			/* restore the cursor position */
X
X	/*
X	 * Now do a block move to update the internal screen image
X	 */
X	d = Realscreen + (Columns * (Rows - 1)) - 1;
X	s = d - (Columns * nlines);
X	e = Realscreen + (Columns * row);
X
X	while (s >= e)
X		*d-- = *s--;
X
X	/*
X	 * Clear the inserted lines
X	 */
X	s = Realscreen + (row * Columns);
X	e = s + (nlines * Columns);
X	while (s < e)
X		*s++ = ' ';
X}
X
X/*
X * s_del(row, nlines) - delete 'nlines' lines at 'row'
X */
Xvoid
Xs_del(row, nlines)
Xint	row;
Xint	nlines;
X{
X	register char	*s, *d, *e;
X	register int	i;
X
X#ifndef BIOS
X	if ( ! CANDL ) return;		/* can't do it */
X#endif
X
X	/* delete the lines */
X	SAVCUR;				/* save position */
X
X	windgoto (Rows-1, 0);		/* go to status line */
X	CLEOL;				/* Clear it */
X	windgoto (row, 0);		/* Go to 1st line-to-del */
X	CRTDL( row, nlines );		/* Delete the lines */
X	RESCUR;				/* Restore the cursor */
X
X	/*
X	 * do a block move to update the internal image
X	 */
X	d = Realscreen + (row * Columns);
X	s = d + (nlines * Columns);
X	e = Realscreen + ((Rows - 1) * Columns);
X
X	while (s < e)
X		*d++ = *s++;
X
X	while (d < e)		/* clear the lines at the bottom */
X		*d++ = ' ';
X}
!EOR!