implement Src; include "sys.m";	sys: Sys;include "draw.m";include "dis.m";	dis: Dis; Src: module{	init: fn(nil: ref Draw->Context, argv: list of string);}; init(nil: ref Draw->Context, argv: list of string){	sys = load Sys Sys->PATH;	dis = load Dis Dis->PATH; 	if(dis != nil){		dis->init();		for(argv = tl argv; argv != nil; argv = tl argv){			s := src(hd argv);			if(s == nil)				s = "?";			sys->print("%s:	%s\n", hd argv, s);		}	}} src(progname: string): string{	disfile := 0;	if (len progname >= 4 && progname[len progname-4:] == ".dis")		disfile = 1;	pathlist: list of string;	if (absolute(progname))		pathlist = list of {""};	else		pathlist = list of {"/dis", "."}; 	err := "";	do {		path: string;		if (hd pathlist != "")			path = hd pathlist + "/" + progname;		else			path = progname; 		npath := path;		if (!disfile)			npath += ".dis";		src := dis->src(npath);		if(src != nil)			return src;		err = sys->sprint("%r");		if (nonexistent(err)) {			# try and find it as a shell script			if (!disfile) {				(ok, info) := sys->stat(path);				if (ok == 0 && (info.mode & Sys->DMDIR) == 0						&& (info.mode & 8r111) != 0)					return path;				else					err = sys->sprint("%r");			}		}		pathlist = tl pathlist;	} while (pathlist != nil && nonexistent(err));	return nil;} absolute(p: string): int{	if (len p < 2)		return 0;	if (p[0] == '/' || p[0] == '#')		return 1;	if (len p < 3 || p[0] != '.')		return 0;	if (p[1] == '/')		return 1;	if (p[1] == '.' && p[2] == '/')		return 1;	return 0;} nonexistent(e: string): int{	errs := array[] of {"does not exist", "directory entry not found"};	for (i := 0; i < len errs; i++){		j := len errs[i];		if (j <= len e && e[len e-j:] == errs[i])			return 1;	}	return 0;}