nedmail.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

helpcmd(Cmd*, Message *m)
{
	int i;

	Bprint(&out, "Commands are of the form [<range>] <command> [args]\n");
	Bprint(&out, "<range> := <addr> | <addr>','<addr>| 'g'<search>\n");
	Bprint(&out, "<addr> := '.' | '$' | '^' | <number> | <search> | <addr>'+'<addr> | <addr>'-'<addr>\n");
	Bprint(&out, "<search> := '/'<regexp>'/' | '?'<regexp>'?' | '%%'<regexp>'%%'\n");
	Bprint(&out, "<command> :=\n");
	for(i = 0; cmdtab[i].cmd != nil; i++)
		Bprint(&out, "%s\n", cmdtab[i].help);
	return m;
}

int
tomailer(char **av)
{
	Waitmsg *w;
	int pid, i;

	// start the mailer and get out of the way
	switch(pid = fork()){
	case -1:
		fprint(2, "can't fork: %r\n");
		return -1;
	case 0:
		Bprint(&out, "!/bin/upas/marshal");
		for(i = 1; av[i]; i++){
			if(strchr(av[i], ' ') != nil)
				Bprint(&out, " '%s'", av[i]);
			else
				Bprint(&out, " %s", av[i]);
		}
		Bprint(&out, "\n");
		Bflush(&out);
		av[0] = "marshal";
		chdir(wd);
		exec("/bin/upas/marshal", av);
		fprint(2, "couldn't exec /bin/upas/marshal\n");
		exits(0);
	default:
		w = wait();
		if(w == nil){
			if(interrupted)
				postnote(PNPROC, pid, "die");
			waitpid();
			return -1;
		}
		if(w->msg[0]){
			fprint(2, "mailer failed: %s\n", w->msg);
			free(w);
			return -1;
		}
		free(w);
		Bprint(&out, "!\n");
		break;
	}
	return 0;
}

//
// like tokenize but obey "" quoting
//
int
tokenize822(char *str, char **args, int max)
{
	int na;
	int intok = 0, inquote = 0;

	if(max <= 0)
		return 0;	
	for(na=0; ;str++)
		switch(*str) {
		case ' ':
		case '\t':
			if(inquote)
				goto Default;
			/* fall through */
		case '\n':
			*str = 0;
			if(!intok)
				continue;
			intok = 0;
			if(na < max)
				continue;
			/* fall through */
		case 0:
			return na;
		case '"':
			inquote ^= 1;
			/* fall through */
		Default:
		default:
			if(intok)
				continue;
			args[na++] = str;
			intok = 1;
		}
}

Message*
rcmd(Cmd *c, Message *m)
{
	char *av[128];
	int i, ai = 1;
	Message *nm;
	char *addr;
	String *path = nil;
	String *rpath;
	String *subject = nil;
	String *from;

	if(m == &top){
		Bprint(&out, "!address\n");
		return nil;
	}

	addr = nil;
	for(nm = m; nm != &top; nm = nm->parent){
 		if(*nm->replyto != 0){
			addr = nm->replyto;
			break;
		}
	}
	if(addr == nil){
		Bprint(&out, "!no reply address\n");
		return nil;
	}

	if(nm == &top){
		print("!noone to reply to\n");
		return nil;
	}

	for(nm = m; nm != &top; nm = nm->parent){
		if(*nm->subject){
			av[ai++] = "-s";
			subject = addrecolon(nm->subject);
			av[ai++] = s_to_c(subject);;
			break;
		}
	}

	av[ai++] = "-R";
	rpath = rooted(s_clone(m->path));
	av[ai++] = s_to_c(rpath);

	if(strchr(c->av[0], 'f') != nil){
		fcmd(c, m);
		av[ai++] = "-F";
	}

	if(strchr(c->av[0], 'R') != nil){
		av[ai++] = "-t";
		av[ai++] = "message/rfc822";
		av[ai++] = "-A";
		path = rooted(extendpath(m->path, "raw"));
		av[ai++] = s_to_c(path);
	}

	for(i = 1; i < c->an && ai < nelem(av)-1; i++)
		av[ai++] = c->av[i];
	from = s_copy(addr);
	ai += tokenize822(s_to_c(from), &av[ai], nelem(av) - ai);
	av[ai] = 0;
	if(tomailer(av) < 0)
		m = nil;
	s_free(path);
	s_free(rpath);
	s_free(subject);
	s_free(from);
	return m;
}

Message*
mcmd(Cmd *c, Message *m)
{
	char **av;
	int i, ai;
	String *path;

	if(m == &top){
		Bprint(&out, "!address\n");
		return nil;
	}

	if(c->an < 2){
		fprint(2, "!usage: M list-of addresses\n");
		return nil;
	}

	ai = 1;
	av = malloc(sizeof(char*)*(c->an + 8));

	av[ai++] = "-t";
	if(m->parent == &top)
		av[ai++] = "message/rfc822";
	else
		av[ai++] = "mime";

	av[ai++] = "-A";
	path = rooted(extendpath(m->path, "raw"));
	av[ai++] = s_to_c(path);

	if(strchr(c->av[0], 'M') == nil)
		av[ai++] = "-n";

	for(i = 1; i < c->an; i++)
		av[ai++] = c->av[i];
	av[ai] = 0;

	if(tomailer(av) < 0)
		m = nil;
	if(path != nil)
		s_free(path);
	free(av);
	return m;
}

Message*
acmd(Cmd *c, Message *m)
{
	char *av[128];
	int i, ai;
	String *from, *to, *cc, *path = nil, *subject = nil;

	if(m == &top){
		Bprint(&out, "!address\n");
		return nil;
	}

	ai = 1;
	if(*m->subject){
		av[ai++] = "-s";
		subject = addrecolon(m->subject);
		av[ai++] = s_to_c(subject);
	}

	if(strchr(c->av[0], 'A') != nil){
		av[ai++] = "-t";
		av[ai++] = "message/rfc822";
		av[ai++] = "-A";
		path = rooted(extendpath(m->path, "raw"));
		av[ai++] = s_to_c(path);
	}

	for(i = 1; i < c->an && ai < nelem(av)-1; i++)
		av[ai++] = c->av[i];
	from = s_copy(m->from);
	ai += tokenize822(s_to_c(from), &av[ai], nelem(av) - ai);
	to = s_copy(m->to);
	ai += tokenize822(s_to_c(to), &av[ai], nelem(av) - ai);
	cc = s_copy(m->cc);
	ai += tokenize822(s_to_c(cc), &av[ai], nelem(av) - ai);
	av[ai] = 0;
	if(tomailer(av) < 0)
		return nil;
	s_free(from);
	s_free(to);
	s_free(cc);
	s_free(subject);
	s_free(path);
	return m;
}

String *
relpath(char *path, String *to)
{
	if (*path=='/' || strncmp(path, "./", 2) == 0
			      || strncmp(path, "../", 3) == 0) {
		to = s_append(to, path);
	} else if(mbpath) {
		to = s_append(to, s_to_c(mbpath));
		to->ptr = strrchr(to->base, '/')+1;
		s_append(to, path);
	}
	return to;
}

int
appendtofile(Message *m, char *part, char *base, int mbox)
{
	String *file, *h;
	int in, out, rv;

	file = extendpath(m->path, part);
	in = open(s_to_c(file), OREAD);
	if(in < 0){
		fprint(2, "!message disappeared\n");
		return -1;
	}

	s_reset(file);

	relpath(base, file);
	if(sysisdir(s_to_c(file))){
		s_append(file, "/");
		if(m->filename && strchr(m->filename, '/') == nil)
			s_append(file, m->filename);
		else {
			s_append(file, "att.XXXXXXXXXXX");
			mktemp(s_to_c(file));
		}
	}
	if(mbox)
		out = open(s_to_c(file), OWRITE);
	else
		out = open(s_to_c(file), OWRITE|OTRUNC);
	if(out < 0){
		out = create(s_to_c(file), OWRITE, 0666);
		if(out < 0){
			fprint(2, "!can't open %s: %r\n", s_to_c(file));
			close(in);
			s_free(file);
			return -1;
		}
	}
	if(mbox)
		seek(out, 0, 2);

	// put on a 'From ' line
	if(mbox){
		while(m->parent != &top)
			m = m->parent;
		h = file2string(m->path, "unixheader");
		fprint(out, "%s", s_to_c(h));
		s_free(h);
	}

	// copy the message escaping what we have to ad adding newlines if we have to
	if(mbox)
		rv = appendfiletombox(in, out);
	else
		rv = appendfiletofile(in, out);

	close(in);
	close(out);

	if(rv >= 0)
		print("!saved in %s\n", s_to_c(file));
	s_free(file);
	return rv;
}

Message*
scmd(Cmd *c, Message *m)
{
	char *file;

	if(m == &top){
		Bprint(&out, "!address\n");
		return nil;
	}

	switch(c->an){
	case 1:
		file = "stored";
		break;
	case 2:
		file = c->av[1];
		break;
	default:
		fprint(2, "!usage: s filename\n");
		return nil;
	}

	if(appendtofile(m, "raw", file, 1) < 0)
		return nil;

	m->stored = 1;
	return m;
}

Message*
wcmd(Cmd *c, Message *m)
{
	char *file;

	if(m == &top){
		Bprint(&out, "!address\n");
		return nil;
	}

	switch(c->an){
	case 2:
		file = c->av[1];
		break;
	case 1:
		if(*m->filename == 0){
			fprint(2, "!usage: w filename\n");
			return nil;
		}
		file = strrchr(m->filename, '/');
		if(file != nil)
			file++;
		else
			file = m->filename;
		break;
	default:
		fprint(2, "!usage: w filename\n");
		return nil;
	}

	if(appendtofile(m, "body", file, 0) < 0)
		return nil;
	m->stored = 1;
	return m;
}

char *specialfile[] =
{
	"pipeto",
	"pipefrom",
	"L.mbox",
	"forward",
	"names"
};

// return 1 if this is a special file
static int
special(String *s)
{
	char *p;
	int i;

	p = strrchr(s_to_c(s), '/');
	if(p == nil)
		p = s_to_c(s);
	else
		p++;
	for(i = 0; i < nelem(specialfile); i++)
		if(strcmp(p, specialfile[i]) == 0)
			return 1;
	return 0;
}

// open the folder using the recipients account name
static String*
foldername(char *rcvr)
{
	char *p;
	int c;
	String *file;
	Dir *d;
	int scarey;

	file = s_new();
	mboxpath("f", user, file, 0);
	d = dirstat(s_to_c(file));

	// if $mail/f exists, store there, otherwise in $mail
	s_restart(file);
	if(d && d->qid.type == QTDIR){
		scarey = 0;
		s_append(file, "f/");
	} else {
		scarey = 1;
	}
	free(d);

	p = strrchr(rcvr, '!');
	if(p != nil)
		rcvr = p+1;

	while(*rcvr && *rcvr != '@'){
		c = *rcvr++;
		if(c == '/')
			c = '_';
		s_putc(file, c);
	}
	s_terminate(file);

	if(scarey && special(file)){
		fprint(2, "!won't overwrite %s\n", s_to_c(file));
		s_free(file);
		return nil;
	}

	return file;
}

Message*
fcmd(Cmd *c, Message *m)
{
	String *folder;

	if(c->an > 1){
		fprint(2, "!usage: f takes no arguments\n");
		return nil;
	}

	if(m == &top){
		Bprint(&out, "!address\n");
		return nil;
	}

	folder = foldername(m->from);
	if(folder == nil)
		return nil;

	if(appendtofile(m, "raw", s_to_c(folder), 1) < 0){
		s_free(folder);
		return nil;
	}
	s_free(folder);

	m->stored = 1;
	return m;
}

void
system(char *cmd, char **av, int in)
{
	int pid;

	switch(pid=fork()){
	case -1:
		return;
	case 0:
		if(in >= 0){
			close(0);
			dup(in, 0);
			close(in);
		}
		if(wd[0] != 0)
			chdir(wd);
		exec(cmd, av);
		fprint(2, "!couldn't exec %s\n", cmd);
		exits(0);
	default:
		if(in >= 0)
			close(in);
		while(waitpid() < 0){
			if(!interrupted)
				break;
			postnote(PNPROC, pid, "die");
			continue;
		}
		break;
	}
}

Message*
bangcmd(Cmd *c, Message *m)
{
	char cmd[4*1024];
	char *p, *e;
	char *av[4];
	int i;

	cmd[0] = 0;
	p = cmd;
	e = cmd+sizeof(cmd);
	for(i = 1; i < c->an; i++)
		p = seprint(p, e, "%s ", c->av[i]);
	av[0] = "rc";
	av[1] = "-c";
	av[2] = cmd;
	av[3] = 0;
	system("/bin/rc", av, -1);
	Bprint(&out, "!\n");
	return m;
}

Message*
xpipecmd(Cmd *c, Message *m, char *part)
{
	char cmd[128];
	char *p, *e;
	char *av[4];
	String *path;
	int i, fd;

	if(c->an < 2){
		Bprint(&out, "!usage: | cmd\n");
		return nil;
	}

	if(m == &top){
		Bprint(&out, "!address\n");
		return nil;
	}

	path = extendpath(m->path, part);
	fd = open(s_to_c(path), OREAD);
	s_free(path);
	if(fd < 0){	// compatibility with older upas/fs
		path = extendpath(m->path, "raw");
		fd = open(s_to_c(path), OREAD);
		s_free(path);
	}
	if(fd < 0){
		fprint(2, "!message disappeared\n");
		return nil;
	}

	p = cmd;
	e = cmd+sizeof(cmd);
	cmd[0] = 0;
	for(i = 1; i < c->an; i++)
		p = seprint(p, e, "%s ", c->av[i]);
	av[0] = "rc";
	av[1] = "-c";
	av[2] = cmd;
	av[3] = 0;
	system("/bin/rc", av, fd);	/* system closes fd */
	Bprint(&out, "!\n");
	return m;
}

Message*
pipecmd(Cmd *c, Message *m)
{
	return xpipecmd(c, m, "body");
}

Message*
rpipecmd(Cmd *c, Message *m)
{
	return xpipecmd(c, m, "rawunix");
}

void
closemb(void)
{
	int fd;

	fd = open("/mail/fs/ctl", ORDWR);
	if(fd < 0)
		sysfatal("can't open /mail/fs/ctl: %r");

	// close current mailbox
	if(*mbname && strcmp(mbname, "mbox") != 0)
		fprint(fd, "close %s", mbname);

	close(fd);
}

int
switchmb(char *file, char *singleton)
{
	char *p;
	int n, fd;
	String *path;
	char buf[256];

	// if the user didn't say anything and there
	// is an mbox mounted already, use that one
	// so that the upas/fs -fdefault default is honored.
	if(file 
	|| (singleton && access(singleton, 0)<0)
	|| (!singleton && access("/mail/fs/mbox", 0)<0)){
		if(file == nil)
			file = "mbox";

		// close current mailbox
		closemb();
		didopen = 1;

		fd = open("/mail/fs/ctl", ORDWR);
		if(fd < 0)
			sysfatal("can't open /mail/fs/ctl: %r");
	
		path = s_new();
	
		// get an absolute path to the mail box
		if(strncmp(file, "./", 2) == 0){
			// resolve path here since upas/fs doesn't know
			// our working directory
			if(getwd(buf, sizeof(buf)-strlen(file)) == nil){
				fprint(2, "!can't get working directory: %s\n", buf);
				return -1;
			}
			s_append(path, buf);
			s_append(path, file+1);
		} else {
			mboxpath(file, user, path, 0);
		}
	
		// make up a handle to use when talking to fs
		p = strrchr(file, '/');
		if(p == nil){
			// if its in the mailbox directory, just use the name
			strncpy(mbname, file, sizeof(mbname));
			mbname[sizeof(mbname)-1] = 0;
		} else {
			// make up a mailbox name
			p = strrchr(s_to_c(path), '/');
			p++;
			if(*p == 0){
				fprint(2, "!bad mbox name");
				return -1;
			}
			strncpy(mbname, p, sizeof(mbname));
			mbname[sizeof(mbname)-1] = 0;
			n = strlen(mbname);
			if(n > Elemlen-12)
				n = Elemlen-12;
			sprint(mbname+n, "%ld", time(0));
		}

		if(fprint(fd, "open %s %s", s_to_c(path), mbname) < 0){
			fprint(2, "!can't 'open %s %s': %r\n", file, mbname);
			s_free(path);
			return -1;
		}
		close(fd);
	}else
	if (singleton && access(singleton, 0)==0
	    && strncmp(singleton, "/mail/fs/", 9) == 0){
		if ((p = strchr(singleton +10, '/')) == nil){
			fprint(2, "!bad mbox name");
			return -1;
		}
		n = p-(singleton+9);
		strncpy(mbname, singleton+9, n);
		mbname[n+1] = 0;
		path = s_reset(nil);
		mboxpath(mbname, user, path, 0);
	}else{
		path = s_reset(nil);
		mboxpath("mbox", user, path, 0);
		strcpy(mbname, "mbox");
	}

	sprint(root, "/mail/fs/%s", mbname);
	if(getwd(wd, sizeof(wd)) == 0)
		wd[0] = 0;
	if(singleton == nil && chdir(root) >= 0)
		strcpy(root, ".");
	rootlen = strlen(root);

	if(mbpath != nil)
		s_free(mbpath);
	mbpath = path;
	return 0;
}

// like tokenize but for into lines
int
lineize(char *s, char **f, int n)
{
	int i;

	for(i = 0; *s && i < n; i++){
		f[i] = s;
		s = strchr(s, '\n');
		if(s == nil)
			break;
		*s++ = 0;
	}
	return i;
}



String*
rooted(String *s)
{
	static char buf[256];

	if(strcmp(root, ".") != 0)
		return s;
	snprint(buf, sizeof(buf), "/mail/fs/%s/%s", mbname, s_to_c(s));
	s_free(s);
	return s_copy(buf);
}

int
plumb(Message *m, Ctype *cp)
{
	String *s;
	Plumbmsg *pm;
	static int fd = -2;

	if(cp->plumbdest == nil)
		return -1;

	if(fd < -1)
		fd = plumbopen("send", OWRITE);
	if(fd < 0)
		return -1;

	pm = mallocz(sizeof(Plumbmsg), 1);
	pm->src = strdup("mail");
	if(*cp->plumbdest)
		pm->dst = strdup(cp->plumbdest);
	pm->wdir = nil;
	pm->type = strdup("text");
	pm->ndata = -1;
	s = rooted(extendpath(m->path, "body"));
	if(cp->ext != nil){
		s_append(s, ".");
		s_append(s, cp->ext);
	}
	pm->data = strdup(s_to_c(s));
	s_free(s);
	plumbsend(fd, pm);
	plumbfree(pm);
	return 0;
}

void
regerror(char*)
{
}

String*
addrecolon(char *s)
{
	String *str;

	if(cistrncmp(s, "re:", 3) != 0){
		str = s_copy("Re: ");
		s_append(str, s);
	} else
		str = s_copy(s);
	return str;
}

void
exitfs(char *rv)
{
	if(startedfs)
		unmount(nil, "/mail/fs");
chdir("/sys/src/cmd/upas/ned");
	exits(rv);
}