implement Script; include "sys.m";	sys: Sys; include "draw.m"; include "string.m";	str: String; include "lock.m";include "modem.m";	modem: Modem;	Device: import modem; include "script.m"; Scriptlim: con 32*1024;		# should be enough for all init(mm: Modem): string{	sys = load Sys Sys->PATH;	modem = mm;	str = load String String->PATH;	if(str == nil)		return sys->sprint("can't load %s: %r", String->PATH);	return nil;} execute(m: ref Modem->Device, scriptinfo: ref ScriptInfo): string{	if(scriptinfo.path != nil) {		if(m.trace)			sys->print("script: using %s\n",scriptinfo.path);		# load the script		err: string;		(scriptinfo.content, err) = scriptload(scriptinfo.path);		if(err != nil)			return err;	}else{		if(m.trace)			sys->print("script: using inline script\n");	}		if(scriptinfo.timeout == 0)		scriptinfo.timeout = 20; 	tend := sys->millisec() + 1000*scriptinfo.timeout; 	for(conv := scriptinfo.content; conv != nil; conv = tl conv){		e, s:	string = nil;		p := hd conv;		if(len p == 0)			continue;		if(m.trace)			sys->print("script: %s\n",p);		if(p[0] == '-') {	# just send			if(len p == 1)				continue;			s = p[1:];		} else {			(n, esl) := sys->tokenize(p, "-");			if(n > 0) {				e = hd esl;				esl = tl esl;				if(n > 1)					s = hd esl;			}		}		if(e  != nil) {			if(match(m, special(e,scriptinfo), tend-sys->millisec()) == 0) {				if(m.trace)					sys->print("script: match failed\n");				return "script failed";			}		}		if(s != nil)			m.send(special(s, scriptinfo));	}	if(m.trace)		sys->print("script: done\n");	return nil;} match(m: ref Modem->Device, s: string, msec: int): int{	for(;;) {		c := m.getc(msec);		if(c ==  '\r')			c = '\n';		if(m.trace)			sys->print("%c",c);		if(c == 0)			return 0;	head:		while(c == s[0]) {			i := 1;			while(i < len s) {				c = m.getc(msec);				if(c == '\r')					c = '\n';				if(m.trace)					sys->print("%c",c);				if(c == 0)					return 0;				if(c != s[i])					continue head;				i++;			}			return 1;		}		if(c == '~')			return 1;	# assume PPP for now	}} ## Expand special script sequences#special(s: string, scriptinfo: ref ScriptInfo): string{	if(s == "$username") 					# special variable		s = scriptinfo.username;	else if(s == "$password") 		s = scriptinfo.password;	return deparse(s);} deparse(s: string): string{	r: string = "";	for(i:=0; i < len s; i++) {		c := s[i];		if(c == '\\'  && i+1 < len s) {			c = s[++i];			case c {			't'	=> c = '\t';			'n'	=> c = '\n';			'r'	=> c = '\r';			'b'	=> c = '\b';			'a'	=> c = '\a';			'v'	=> c = '\v';			'0'	=> c = '\0';			'$'	=> c = '$';			'u'	=> 				if(i+4 < len s) {					i++;					(c, nil) = str->toint(s[i:i+4], 16);					i+=3;				}			}		}		r[len r] = c;	}	return r;} scriptload(path: string): (list of string, string){	dfd := sys->open(path, Sys->OREAD);	if(dfd == nil)		return (nil, sys->sprint("can't open script %s: %r", path)); 	b := array[Scriptlim] of byte;	n := sys->read(dfd, b, len b);	if(n < 0)		return (nil, sys->sprint("can't read script %s: %r", path));    	(nil, script) := sys->tokenize(string b[0:n], "\n");	return (script, nil);}