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

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <cursor.h>
#include <mouse.h>
#include <keyboard.h>
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
#include "dat.h"
#include "edit.h"
#include "fns.h"

int	Glooping;
int	nest;
char	Enoname[] = "no file name given";

Address	addr;
File	*menu;
Rangeset	sel;
extern	Text*	curtext;
Rune	*collection;
int	ncollection;

int	append(File*, Cmd*, long);
int	pdisplay(File*);
void	pfilename(File*);
void	looper(File*, Cmd*, int);
void	filelooper(Cmd*, int);
void	linelooper(File*, Cmd*);
Address	lineaddr(long, Address, int);
int	filematch(File*, String*);
File	*tofile(String*);
Rune*	cmdname(File *f, String *s, int);
void	runpipe(Text*, int, Rune*, int, int);

void
clearcollection(void)
{
	free(collection);
	collection = nil;
	ncollection = 0;
}

void
resetxec(void)
{
	Glooping = nest = 0;
	clearcollection();
}

void
mkaddr(Address *a, File *f)
{
	a->r.q0 = f->curtext->q0;
	a->r.q1 = f->curtext->q1;
	a->f = f;
}

int
cmdexec(Text *t, Cmd *cp)
{
	int i;
	Addr *ap;
	File *f;
	Window *w;
	Address dot;

	if(t == nil)
		w = nil;
	else
		w = t->w;
	if(w==nil && (cp->addr==0 || cp->addr->type!='"') &&
	    !utfrune("bBnqUXY!", cp->cmdc) &&
	    !(cp->cmdc=='D' && cp->text))
		editerror("no current window");
	i = cmdlookup(cp->cmdc);	/* will be -1 for '{' */
	f = nil;
	if(t && t->w){
		t = &t->w->body;
		f = t->file;
		f->curtext = t;
	}
	if(i>=0 && cmdtab[i].defaddr != aNo){
		if((ap=cp->addr)==0 && cp->cmdc!='\n'){
			cp->addr = ap = newaddr();
			ap->type = '.';
			if(cmdtab[i].defaddr == aAll)
				ap->type = '*';
		}else if(ap && ap->type=='"' && ap->next==0 && cp->cmdc!='\n'){
			ap->next = newaddr();
			ap->next->type = '.';
			if(cmdtab[i].defaddr == aAll)
				ap->next->type = '*';
		}
		if(cp->addr){	/* may be false for '\n' (only) */
			static Address none = {0,0,nil};
			if(f){
				mkaddr(&dot, f);
				addr = cmdaddress(ap, dot, 0);
			}else	/* a " */
				addr = cmdaddress(ap, none, 0);
			f = addr.f;
			t = f->curtext;
		}
	}
	switch(cp->cmdc){
	case '{':
		mkaddr(&dot, f);
		if(cp->addr != nil)
			dot = cmdaddress(cp->addr, dot, 0);
		for(cp = cp->cmd; cp; cp = cp->next){
			if(dot.r.q1 > t->file->nc)
				editerror("dot extends past end of buffer during { command");
			t->q0 = dot.r.q0;
			t->q1 = dot.r.q1;
			cmdexec(t, cp);
		}
		break;
	default:
		if(i < 0)
			editerror("unknown command %c in cmdexec", cp->cmdc);
		i = (*cmdtab[i].fn)(t, cp);
		return i;
	}
	return 1;
}

char*
edittext(Window *w, int q, Rune *r, int nr)
{
	File *f;

	f = w->body.file;
	switch(editing){
	case Inactive:
		return "permission denied";
	case Inserting:
		eloginsert(f, q, r, nr);
		return nil;
	case Collecting:
		collection = runerealloc(collection, ncollection+nr+1);
		runemove(collection+ncollection, r, nr);
		ncollection += nr;
		collection[ncollection] = '\0';
		return nil;
	default:
		return "unknown state in edittext";
	}
}

/* string is known to be NUL-terminated */
Rune*
filelist(Text *t, Rune *r, int nr)
{
	if(nr == 0)
		return nil;
	r = skipbl(r, nr, &nr);
	if(r[0] != '<')
		return runestrdup(r);
	/* use < command to collect text */
	clearcollection();
	runpipe(t, '<', r+1, nr-1, Collecting);
	return collection;
}

int
a_cmd(Text *t, Cmd *cp)
{
	return append(t->file, cp, addr.r.q1);
}

int
b_cmd(Text*, Cmd *cp)
{
	File *f;

	f = tofile(cp->text);
	if(nest == 0)
		pfilename(f);
	curtext = f->curtext;
	return TRUE;
}

int
B_cmd(Text *t, Cmd *cp)
{
	Rune *list, *r, *s;
	int nr;

	list = filelist(t, cp->text->r, cp->text->n);
	if(list == nil)
		editerror(Enoname);
	r = list;
	nr = runestrlen(r);
	r = skipbl(r, nr, &nr);
	if(nr == 0)
		new(t, t, nil, 0, 0, r, 0);
	else while(nr > 0){
		s = findbl(r, nr, &nr);
		*s = '\0';
		new(t, t, nil, 0, 0, r, runestrlen(r));
		if(nr > 0)
			r = skipbl(s+1, nr-1, &nr);
	}
	clearcollection();
	return TRUE;
}

int
c_cmd(Text *t, Cmd *cp)
{
	elogreplace(t->file, addr.r.q0, addr.r.q1, cp->text->r, cp->text->n);
	t->q0 = addr.r.q0;
	t->q1 = addr.r.q0;
	return TRUE;
}

int
d_cmd(Text *t, Cmd*)
{
	if(addr.r.q1 > addr.r.q0)
		elogdelete(t->file, addr.r.q0, addr.r.q1);
	t->q0 = addr.r.q0;
	t->q1 = addr.r.q0;
	return TRUE;
}

void
D1(Text *t)
{
	if(t->w->body.file->ntext>1 || winclean(t->w, FALSE))
		colclose(t->col, t->w, TRUE);
}

int
D_cmd(Text *t, Cmd *cp)
{
	Rune *list, *r, *s, *n;
	int nr, nn;
	Window *w;
	Runestr dir, rs;
	char buf[128];

	list = filelist(t, cp->text->r, cp->text->n);
	if(list == nil){
		D1(t);
		return TRUE;
	}
	dir = dirname(t, nil, 0);
	r = list;
	nr = runestrlen(r);
	r = skipbl(r, nr, &nr);
	do{
		s = findbl(r, nr, &nr);
		*s = '\0';
		/* first time through, could be empty string, meaning delete file empty name */
		nn = runestrlen(r);
		if(r[0]=='/' || nn==0 || dir.nr==0){
			rs.r = runestrdup(r);
			rs.nr = nn;
		}else{
			n = runemalloc(dir.nr+1+nn);
			runemove(n, dir.r, dir.nr);
			n[dir.nr] = '/';
			runemove(n+dir.nr+1, r, nn);
			rs = cleanrname((Runestr){n, dir.nr+1+nn});
		}
		w = lookfile(rs.r, rs.nr);
		if(w == nil){
			snprint(buf, sizeof buf, "no such file %.*S", rs.nr, rs.r);
			free(rs.r);
			editerror(buf);
		}
		free(rs.r);
		D1(&w->body);
		if(nr > 0)
			r = skipbl(s+1, nr-1, &nr);
	}while(nr > 0);
	clearcollection();
	free(dir.r);
	return TRUE;
}

static int
readloader(void *v, uint q0, Rune *r, int nr)
{
	if(nr > 0)
		eloginsert(v, q0, r, nr);
	return 0;
}

int
e_cmd(Text *t, Cmd *cp)
{
	Rune *name;
	File *f;
	int i, isdir, q0, q1, fd, nulls, samename, allreplaced;
	char *s, tmp[128];
	Dir *d;

	f = t->file;
	q0 = addr.r.q0;
	q1 = addr.r.q1;
	if(cp->cmdc == 'e'){
		if(winclean(t->w, TRUE)==FALSE)
			editerror("");	/* winclean generated message already */
		q0 = 0;
		q1 = f->nc;
	}
	allreplaced = (q0==0 && q1==f->nc);
	name = cmdname(f, cp->text, cp->cmdc=='e');
	if(name == nil)
		editerror(Enoname);
	i = runestrlen(name);
	samename = runeeq(name, i, t->file->name, t->file->nname);
	s = runetobyte(name, i);
	free(name);
	fd = open(s, OREAD);
	if(fd < 0){
		snprint(tmp, sizeof tmp, "can't open %s: %r", s);
		free(s);
		editerror(tmp);
	}
	d = dirfstat(fd);
	isdir = (d!=nil && (d->qid.type&QTDIR));
	free(d);
	if(isdir){
		close(fd);
		snprint(tmp, sizeof tmp, "%s is a directory", s);
		free(s);
		editerror(tmp);
	}
	elogdelete(f, q0, q1);
	nulls = 0;
	loadfile(fd, q1, &nulls, readloader, f);
	free(s);
	close(fd);
	if(nulls)
		warning(nil, "%s: NUL bytes elided\n", s);
	else if(allreplaced && samename)
		f->editclean = TRUE;
	return TRUE;
}

int
f_cmd(Text *t, Cmd *cp)
{
	Rune *name;
	String *str;
	String empty;

	if(cp->text == nil){
		empty.n = 0;
		empty.r = L"";
		str = &empty;
	}else
		str = cp->text;
	name = cmdname(t->file, str, TRUE);
	free(name);
	pfilename(t->file);
	return TRUE;
}

int
g_cmd(Text *t, Cmd *cp)
{
	if(t->file != addr.f){
		warning(nil, "internal error: g_cmd f!=addr.f\n");
		return FALSE;
	}
	if(rxcompile(cp->re->r) == FALSE)
		editerror("bad regexp in g command");
	if(rxexecute(t, nil, addr.r.q0, addr.r.q1, &sel) ^ cp->cmdc=='v'){
		t->q0 = addr.r.q0;
		t->q1 = addr.r.q1;
		return cmdexec(t, cp->cmd);
	}
	return TRUE;
}

int
i_cmd(Text *t, Cmd *cp)
{
	return append(t->file, cp, addr.r.q0);
}

void
copy(File *f, Address addr2)
{
	long p;
	int ni;
	Rune *buf;

	buf = fbufalloc();
	for(p=addr.r.q0; p<addr.r.q1; p+=ni){
		ni = addr.r.q1-p;
		if(ni > RBUFSIZE)
			ni = RBUFSIZE;
		bufread(f, p, buf, ni);
		eloginsert(addr2.f, addr2.r.q1, buf, ni);
	}
	fbuffree(buf);
}

void
move(File *f, Address addr2)
{
	if(addr.f!=addr2.f || addr.r.q1<=addr2.r.q0){
		elogdelete(f, addr.r.q0, addr.r.q1);
		copy(f, addr2);
	}else if(addr.r.q0 >= addr2.r.q1){
		copy(f, addr2);
		elogdelete(f, addr.r.q0, addr.r.q1);
	}else
		error("move overlaps itself");
}

int
m_cmd(Text *t, Cmd *cp)
{
	Address dot, addr2;

	mkaddr(&dot, t->file);
	addr2 = cmdaddress(cp->mtaddr, dot, 0);
	if(cp->cmdc == 'm')
		move(t->file, addr2);
	else
		copy(t->file, addr2);
	return TRUE;
}

int
p_cmd(Text *t, Cmd*)
{
	return pdisplay(t->file);
}

int
s_cmd(Text *t, Cmd *cp)
{
	int i, j, k, c, m, n, nrp, didsub;
	long p1, op, delta;
	String *buf;
	Rangeset *rp;
	char *err;
	Rune *rbuf;

	n = cp->num;
	op= -1;
	if(rxcompile(cp->re->r) == FALSE)
		editerror("bad regexp in s command");
	nrp = 0;
	rp = nil;
	delta = 0;
	didsub = FALSE;
	for(p1 = addr.r.q0; p1<=addr.r.q1 && rxexecute(t, nil, p1, addr.r.q1, &sel); ){
		if(sel.r[0].q0 == sel.r[0].q1){	/* empty match? */
			if(sel.r[0].q0 == op){
				p1++;
				continue;
			}
			p1 = sel.r[0].q1+1;
		}else
			p1 = sel.r[0].q1;
		op = sel.r[0].q1;
		if(--n>0)
			continue;
		nrp++;
		rp = erealloc(rp, nrp*sizeof(Rangeset));
		rp[nrp-1] = sel;
	}
	rbuf = fbufalloc();
	buf = allocstring(0);
	for(m=0; m<nrp; m++){
		buf->n = 0;
		buf->r[0] = L'\0';
		sel = rp[m];
		for(i = 0; i<cp->text->n; i++)
			if((c = cp->text->r[i])=='\\' && i<cp->text->n-1){
				c = cp->text->r[++i];
				if('1'<=c && c<='9') {
					j = c-'0';
					if(sel.r[j].q1-sel.r[j].q0>RBUFSIZE){
						err = "replacement string too long";
						goto Err;
					}
					bufread(t->file, sel.r[j].q0, rbuf, sel.r[j].q1-sel.r[j].q0);
					for(k=0; k<sel.r[j].q1-sel.r[j].q0; k++)
						Straddc(buf, rbuf[k]);
				}else
				 	Straddc(buf, c);
			}else if(c!='&')
				Straddc(buf, c);
			else{
				if(sel.r[0].q1-sel.r[0].q0>RBUFSIZE){
					err = "right hand side too long in substitution";
					goto Err;
				}
				bufread(t->file, sel.r[0].q0, rbuf, sel.r[0].q1-sel.r[0].q0);
				for(k=0; k<sel.r[0].q1-sel.r[0].q0; k++)
					Straddc(buf, rbuf[k]);
			}
		elogreplace(t->file, sel.r[0].q0, sel.r[0].q1,  buf->r, buf->n);
		delta -= sel.r[0].q1-sel.r[0].q0;
		delta += buf->n;
		didsub = 1;
		if(!cp->flag)
			break;
	}
	free(rp);
	freestring(buf);
	fbuffree(rbuf);
	if(!didsub && nest==0)
		editerror("no substitution");
	t->q0 = addr.r.q0;
	t->q1 = addr.r.q1;
	return TRUE;

Err:
	free(rp);
	freestring(buf);
	fbuffree(rbuf);
	editerror(err);
	return FALSE;
}

int
u_cmd(Text *t, Cmd *cp)
{
	int n, oseq, flag;

	n = cp->num;
	flag = TRUE;
	if(n < 0){
		n = -n;
		flag = FALSE;
	}
	oseq = -1;
	while(n-->0 && t->file->seq!=0 && t->file->seq!=oseq){
		oseq = t->file->seq;
		undo(t, nil, nil, flag, 0, nil, 0);
	}
	return TRUE;
}

int
w_cmd(Text *t, Cmd *cp)
{
	Rune *r;
	File *f;

	f = t->file;
	if(f->seq == seq)
		editerror("can't write file with pending modifications");
	r = cmdname(f, cp->text, FALSE);
	if(r == nil)
		editerror("no name specified for 'w' command");
	putfile(f, addr.r.q0, addr.r.q1, r, runestrlen(r));
	/* r is freed by putfile */
	return TRUE;
}

int
x_cmd(Text *t, Cmd *cp)
{
	if(cp->re)
		looper(t->file, cp, cp->cmdc=='x');
	else
		linelooper(t->file, cp);
	return TRUE;
}

int
X_cmd(Text*, Cmd *cp)
{
	filelooper(cp, cp->cmdc=='X');
	return TRUE;
}

void
runpipe(Text *t, int cmd, Rune *cr, int ncr, int state)
{
	Rune *r, *s;
	int n;
	Runestr dir;
	Window *w;

	r = skipbl(cr, ncr, &n);
	if(n == 0)
		editerror("no command specified for %c", cmd);
	w = nil;
	if(state == Inserting){
		w = t->w;
		t->q0 = addr.r.q0;
		t->q1 = addr.r.q1;
		if(cmd == '<' || cmd=='|')
			elogdelete(t->file, t->q0, t->q1);
	}
	s = runemalloc(n+2);
	s[0] = cmd;
	runemove(s+1, r, n);
	n++;
	dir.r = nil;
	dir.nr = 0;
	if(t != nil)
		dir = dirname(t, nil, 0);
	if(dir.nr==1 && dir.r[0]=='.'){	/* sigh */
		free(dir.r);
		dir.r = nil;
		dir.nr = 0;
	}
	editing = state;
	if(t!=nil && t->w!=nil)
		incref(t->w);	/* run will decref */
	run(w, runetobyte(s, n), dir.r, dir.nr, TRUE, nil, nil, TRUE);
	free(s);
	if(t!=nil && t->w!=nil)
		winunlock(t->w);
	qunlock(&row);
	recvul(cedit);
	qlock(&row);
	editing = Inactive;
	if(t!=nil && t->w!=nil)
		winlock(t->w, 'M');
}

int
pipe_cmd(Text *t, Cmd *cp)
{
	runpipe(t, cp->cmdc, cp->text->r, cp->text->n, Inserting);
	return TRUE;
}

long
nlcount(Text *t, long q0, long q1)
{
	long nl;
	Rune *buf;
	int i, nbuf;

	buf = fbufalloc();
	nbuf = 0;
	i = nl = 0;
	while(q0 < q1){
		if(i == nbuf){
			nbuf = q1-q0;
			if(nbuf > RBUFSIZE)
				nbuf = RBUFSIZE;
			bufread(t->file, q0, buf, nbuf);
			i = 0;
		}
		if(buf[i++] == '\n')
			nl++;
		q0++;
	}
	fbuffree(buf);
	return nl;
}