path.exists("/etc/passwd",function(res){
console.log(res);
});
path.extname("/home/name/index.html"); // .html
path.basename("dir"[,ext]);//ext代表后缀名
ex:path.basename("/home/name/index.html");//index.html
ex:path.basename("/home/name/index.html",".html");//index
path.dirname("/home/name/index.html");// /home/name
path.join("home","name","index.html");// /home/name/index.html