ecmd.c

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

void
printposn(Text *t, int charsonly)
{
	long l1, l2;

	if (t != nil && t->file != nil && t->file->name != nil)
		warning(nil, "%.*S:", t->file->nname, t->file->name);
	if(!charsonly){
		l1 = 1+nlcount(t, 0, addr.r.q0);
		l2 = l1+nlcount(t, addr.r.q0, addr.r.q1);
		/* check if addr ends with '\n' */
		if(addr.r.q1>0 && addr.r.q1>addr.r.q0 && textreadc(t, addr.r.q1-1)=='\n')
			--l2;
		warning(nil, "%lud", l1);
		if(l2 != l1)
			warning(nil, ",%lud", l2);
		warning(nil, "\n");
		return;
	}
	warning(nil, "#%d", addr.r.q0);
	if(addr.r.q1 != addr.r.q0)
		warning(nil, ",#%d", addr.r.q1);
	warning(nil, "\n");
}

int
eq_cmd(Text *t, Cmd *cp)
{
	int charsonly;

	switch(cp->text->n){
	case 0:
		charsonly = FALSE;
		break;
	case 1:
		if(cp->text->r[0] == '#'){
			charsonly = TRUE;
			break;
		}
	default:
		SET(charsonly);
		editerror("newline expected");
	}
	printposn(t, charsonly);
	return TRUE;
}

int
nl_cmd(Text *t, Cmd *cp)
{
	Address a;
	File *f;

	f = t->file;
	if(cp->addr == 0){
		/* First put it on newline boundaries */
		mkaddr(&a, f);
		addr = lineaddr(0, a, -1);
		a = lineaddr(0, a, 1);
		addr.r.q1 = a.r.q1;
		if(addr.r.q0==t->q0 && addr.r.q1==t->q1){
			mkaddr(&a, f);
			addr = lineaddr(1, a, 1);
		}
	}
	textshow(t, addr.r.q0, addr.r.q1, 1);
	return TRUE;
}

int
append(File *f, Cmd *cp, long p)
{
	if(cp->text->n > 0)
		eloginsert(f, p, cp->text->r, cp->text->n);
	f->curtext->q0 = p;
	f->curtext->q1 = p;
	return TRUE;
}

int
pdisplay(File *f)
{
	long p1, p2;
	int np;
	Rune *buf;

	p1 = addr.r.q0;
	p2 = addr.r.q1;
	if(p2 > f->nc)
		p2 = f->nc;
	buf = fbufalloc();
	while(p1 < p2){
		np = p2-p1;
		if(np>RBUFSIZE-1)
			np = RBUFSIZE-1;
		bufread(f, p1, buf, np);
		buf[np] = L'\0';
		warning(nil, "%S", buf);
		p1 += np;
	}
	fbuffree(buf);
	f->curtext->q0 = addr.r.q0;
	f->curtext->q1 = addr.r.q1;
	return TRUE;
}

void
pfilename(File *f)
{
	int dirty;
	Window *w;

	w = f->curtext->w;
	/* same check for dirty as in settag, but we know ncache==0 */
	dirty = !w->isdir && !w->isscratch && f->mod;
	warning(nil, "%c%c%c %.*S\n", " '"[dirty],
		'+', " ."[curtext!=nil && curtext->file==f], f->nname, f->name);
}

void
loopcmd(File *f, Cmd *cp, Range *rp, long nrp)
{
	long i;

	for(i=0; i<nrp; i++){
		f->curtext->q0 = rp[i].q0;
		f->curtext->q1 = rp[i].q1;
		cmdexec(f->curtext, cp);
	}
}

void
looper(File *f, Cmd *cp, int xy)
{
	long p, op, nrp;
	Range r, tr;
	Range *rp;

	r = addr.r;
	op= xy? -1 : r.q0;
	nest++;
	if(rxcompile(cp->re->r) == FALSE)
		editerror("bad regexp in %c command", cp->cmdc);
	nrp = 0;
	rp = nil;
	for(p = r.q0; p<=r.q1; ){
		if(!rxexecute(f->curtext, nil, p, r.q1, &sel)){ /* no match, but y should still run */
			if(xy || op>r.q1)
				break;
			tr.q0 = op, tr.q1 = r.q1;
			p = r.q1+1;	/* exit next loop */
		}else{
			if(sel.r[0].q0==sel.r[0].q1){	/* empty match? */
				if(sel.r[0].q0==op){
					p++;
					continue;
				}
				p = sel.r[0].q1+1;
			}else
				p = sel.r[0].q1;
			if(xy)
				tr = sel.r[0];
			else
				tr.q0 = op, tr.q1 = sel.r[0].q0;
		}
		op = sel.r[0].q1;
		nrp++;
		rp = erealloc(rp, nrp*sizeof(Range));
		rp[nrp-1] = tr;
	}
	loopcmd(f, cp->cmd, rp, nrp);
	free(rp);
	--nest;
}

void
linelooper(File *f, Cmd *cp)
{
	long nrp, p;
	Range r, linesel;
	Address a, a3;
	Range *rp;

	nest++;
	nrp = 0;
	rp = nil;
	r = addr.r;
	a3.f = f;
	a3.r.q0 = a3.r.q1 = r.q0;
	a = lineaddr(0, a3, 1);
	linesel = a.r;
	for(p = r.q0; p<r.q1; p = a3.r.q1){
		a3.r.q0 = a3.r.q1;
		if(p!=r.q0 || linesel.q1==p){
			a = lineaddr(1, a3, 1);
			linesel = a.r;
		}
		if(linesel.q0 >= r.q1)
			break;
		if(linesel.q1 >= r.q1)
			linesel.q1 = r.q1;
		if(linesel.q1 > linesel.q0)
			if(linesel.q0>=a3.r.q1 && linesel.q1>a3.r.q1){
				a3.r = linesel;
				nrp++;
				rp = erealloc(rp, nrp*sizeof(Range));
				rp[nrp-1] = linesel;
				continue;
			}
		break;
	}
	loopcmd(f, cp->cmd, rp, nrp);
	free(rp);
	--nest;
}

struct Looper
{
	Cmd *cp;
	int	XY;
	Window	**w;
	int	nw;
} loopstruct;	/* only one; X and Y can't nest */

void
alllooper(Window *w, void *v)
{
	Text *t;
	struct Looper *lp;
	Cmd *cp;

	lp = v;
	cp = lp->cp;
//	if(w->isscratch || w->isdir)
//		return;
	t = &w->body;
	/* only use this window if it's the current window for the file */
	if(t->file->curtext != t)
		return;
//	if(w->nopen[QWevent] > 0)
//		return;
	/* no auto-execute on files without names */
	if(cp->re==nil && t->file->nname==0)
		return;
	if(cp->re==nil || filematch(t->file, cp->re)==lp->XY){
		lp->w = erealloc(lp->w, (lp->nw+1)*sizeof(Window*));
		lp->w[lp->nw++] = w;
	}
}

void
alllocker(Window *w, void *v)
{
	if(v)
		incref(w);
	else
		winclose(w);
}

void
filelooper(Cmd *cp, int XY)
{
	int i;

	if(Glooping++)
		editerror("can't nest %c command", "YX"[XY]);
	nest++;

	loopstruct.cp = cp;
	loopstruct.XY = XY;
	if(loopstruct.w)	/* error'ed out last time */
		free(loopstruct.w);
	loopstruct.w = nil;
	loopstruct.nw = 0;
	allwindows(alllooper, &loopstruct);
	/*
	 * add a ref to all windows to keep safe windows accessed by X
	 * that would not otherwise have a ref to hold them up during
	 * the shenanigans.  note this with globalincref so that any
	 * newly created windows start with an extra reference.
	 */
	allwindows(alllocker, (void*)1);
	globalincref = 1;
	for(i=0; i<loopstruct.nw; i++)
		cmdexec(&loopstruct.w[i]->body, cp->cmd);
	allwindows(alllocker, (void*)0);
	globalincref = 0;
	free(loopstruct.w);
	loopstruct.w = nil;

	--Glooping;
	--nest;
}

void
nextmatch(File *f, String *r, long p, int sign)
{
	if(rxcompile(r->r) == FALSE)
		editerror("bad regexp in command address");
	if(sign >= 0){
		if(!rxexecute(f->curtext, nil, p, 0x7FFFFFFFL, &sel))
			editerror("no match for regexp");
		if(sel.r[0].q0==sel.r[0].q1 && sel.r[0].q0==p){
			if(++p>f->nc)
				p = 0;
			if(!rxexecute(f->curtext, nil, p, 0x7FFFFFFFL, &sel))
				editerror("address");
		}
	}else{
		if(!rxbexecute(f->curtext, p, &sel))
			editerror("no match for regexp");
		if(sel.r[0].q0==sel.r[0].q1 && sel.r[0].q1==p){
			if(--p<0)
				p = f->nc;
			if(!rxbexecute(f->curtext, p, &sel))
				editerror("address");
		}
	}
}

File	*matchfile(String*);
Address	charaddr(long, Address, int);
Address	lineaddr(long, Address, int);

Address
cmdaddress(Addr *ap, Address a, int sign)
{
	File *f = a.f;
	Address a1, a2;

	do{
		switch(ap->type){
		case 'l':
		case '#':
			a = (*(ap->type=='#'?charaddr:lineaddr))(ap->num, a, sign);
			break;

		case '.':
			mkaddr(&a, f);
			break;

		case '$':
			a.r.q0 = a.r.q1 = f->nc;
			break;

		case '\'':
editerror("can't handle '");
//			a.r = f->mark;
			break;

		case '?':
			sign = -sign;
			if(sign == 0)
				sign = -1;
			/* fall through */
		case '/':
			nextmatch(f, ap->re, sign>=0? a.r.q1 : a.r.q0, sign);
			a.r = sel.r[0];
			break;

		case '"':
			f = matchfile(ap->re);
			mkaddr(&a, f);
			break;

		case '*':
			a.r.q0 = 0, a.r.q1 = f->nc;
			return a;

		case ',':
		case ';':
			if(ap->left)
				a1 = cmdaddress(ap->left, a, 0);
			else
				a1.f = a.f, a1.r.q0 = a1.r.q1 = 0;
			if(ap->type == ';'){
				f = a1.f;
				a = a1;
				f->curtext->q0 = a1.r.q0;
				f->curtext->q1 = a1.r.q1;
			}
			if(ap->next)
				a2 = cmdaddress(ap->next, a, 0);
			else
				a2.f = a.f, a2.r.q0 = a2.r.q1 = f->nc;
			if(a1.f != a2.f)
				editerror("addresses in different files");
			a.f = a1.f, a.r.q0 = a1.r.q0, a.r.q1 = a2.r.q1;
			if(a.r.q1 < a.r.q0)
				editerror("addresses out of order");
			return a;

		case '+':
		case '-':
			sign = 1;
			if(ap->type == '-')
				sign = -1;
			if(ap->next==0 || ap->next->type=='+' || ap->next->type=='-')
				a = lineaddr(1L, a, sign);
			break;
		default:
			error("cmdaddress");
			return a;
		}
	}while(ap = ap->next);	/* assign = */
	return a;
}

struct Tofile{
	File		*f;
	String	*r;
};

void
alltofile(Window *w, void *v)
{
	Text *t;
	struct Tofile *tp;

	tp = v;
	if(tp->f != nil)
		return;
	if(w->isscratch || w->isdir)
		return;
	t = &w->body;
	/* only use this window if it's the current window for the file */
	if(t->file->curtext != t)
		return;
//	if(w->nopen[QWevent] > 0)
//		return;
	if(runeeq(tp->r->r, tp->r->n, t->file->name, t->file->nname))
		tp->f = t->file;
}

File*
tofile(String *r)
{
	struct Tofile t;
	String rr;

	rr.r = skipbl(r->r, r->n, &rr.n);
	t.f = nil;
	t.r = &rr;
	allwindows(alltofile, &t);
	if(t.f == nil)
		editerror("no such file\"%S\"", rr.r);
	return t.f;
}

void
allmatchfile(Window *w, void *v)
{
	struct Tofile *tp;
	Text *t;

	tp = v;
	if(w->isscratch || w->isdir)
		return;
	t = &w->body;
	/* only use this window if it's the current window for the file */
	if(t->file->curtext != t)
		return;
//	if(w->nopen[QWevent] > 0)
//		return;
	if(filematch(w->body.file, tp->r)){
		if(tp->f != nil)
			editerror("too many files match \"%S\"", tp->r->r);
		tp->f = w->body.file;
	}
}

File*
matchfile(String *r)
{
	struct Tofile tf;

	tf.f = nil;
	tf.r = r;
	allwindows(allmatchfile, &tf);

	if(tf.f == nil)
		editerror("no file matches \"%S\"", r->r);
	return tf.f;
}

int
filematch(File *f, String *r)
{
	char *buf;
	Rune *rbuf;
	Window *w;
	int match, i, dirty;
	Rangeset s;

	/* compile expr first so if we get an error, we haven't allocated anything */
	if(rxcompile(r->r) == FALSE)
		editerror("bad regexp in file match");
	buf = fbufalloc();
	w = f->curtext->w;
	/* same check for dirty as in settag, but we know ncache==0 */
	dirty = !w->isdir && !w->isscratch && f->mod;
	snprint(buf, BUFSIZE, "%c%c%c %.*S\n", " '"[dirty],
		'+', " ."[curtext!=nil && curtext->file==f], f->nname, f->name);
	rbuf = bytetorune(buf, &i);
	fbuffree(buf);
	match = rxexecute(nil, rbuf, 0, i, &s);
	free(rbuf);
	return match;
}

Address
charaddr(long l, Address addr, int sign)
{
	if(sign == 0)
		addr.r.q0 = addr.r.q1 = l;
	else if(sign < 0)
		addr.r.q1 = addr.r.q0 -= l;
	else if(sign > 0)
		addr.r.q0 = addr.r.q1 += l;
	if(addr.r.q0<0 || addr.r.q1>addr.f->nc)
		editerror("address out of range");
	return addr;
}

Address
lineaddr(long l, Address addr, int sign)
{
	int n;
	int c;
	File *f = addr.f;
	Address a;
	long p;

	a.f = f;
	if(sign >= 0){
		if(l == 0){
			if(sign==0 || addr.r.q1==0){
				a.r.q0 = a.r.q1 = 0;
				return a;
			}
			a.r.q0 = addr.r.q1;
			p = addr.r.q1-1;
		}else{
			if(sign==0 || addr.r.q1==0){
				p = 0;
				n = 1;
			}else{
				p = addr.r.q1-1;
				n = textreadc(f->curtext, p++)=='\n';
			}
			while(n < l){
				if(p >= f->nc)
					editerror("address out of range");
				if(textreadc(f->curtext, p++) == '\n')
					n++;
			}
			a.r.q0 = p;
		}
		while(p < f->nc && textreadc(f->curtext, p++)!='\n')
			;
		a.r.q1 = p;
	}else{
		p = addr.r.q0;
		if(l == 0)
			a.r.q1 = addr.r.q0;
		else{
			for(n = 0; n<l; ){	/* always runs once */
				if(p == 0){
					if(++n != l)
						editerror("address out of range");
				}else{
					c = textreadc(f->curtext, p-1);
					if(c != '\n' || ++n != l)
						p--;
				}
			}
			a.r.q1 = p;
			if(p > 0)
				p--;
		}
		while(p > 0 && textreadc(f->curtext, p-1)!='\n')	/* lines start after a newline */
			p--;
		a.r.q0 = p;
	}
	return a;
}

struct Filecheck
{
	File	*f;
	Rune	*r;
	int nr;
};

void
allfilecheck(Window *w, void *v)
{
	struct Filecheck *fp;
	File *f;

	fp = v;
	f = w->body.file;
	if(w->body.file == fp->f)
		return;
	if(runeeq(fp->r, fp->nr, f->name, f->nname))
		warning(nil, "warning: duplicate file name \"%.*S\"\n", fp->nr, fp->r);
}

Rune*
cmdname(File *f, String *str, int set)
{
	Rune *r, *s;
	int n;
	struct Filecheck fc;
	Runestr newname;

	r = nil;
	n = str->n;
	s = str->r;
	if(n == 0){
		/* no name; use existing */
		if(f->nname == 0)
			return nil;
		r = runemalloc(f->nname+1);
		runemove(r, f->name, f->nname);
		return r;
	}
	s = skipbl(s, n, &n);
	if(n == 0)
		goto Return;

	if(s[0] == '/'){
		r = runemalloc(n+1);
		runemove(r, s, n);
	}else{
		newname = dirname(f->curtext, runestrdup(s), n);
		n = newname.nr;
		r = runemalloc(n+1);	/* NUL terminate */
		runemove(r, newname.r, n);
		free(newname.r);
	}
	fc.f = f;
	fc.r = r;
	fc.nr = n;
	allwindows(allfilecheck, &fc);
	if(f->nname == 0)
		set = TRUE;

    Return:
	if(set && !runeeq(r, n, f->name, f->nname)){
		filemark(f);
		f->mod = TRUE;
		f->curtext->w->dirty = TRUE;
		winsetname(f->curtext->w, r, n);
	}
	return r;
}