http的get示例

return new Promise(function(resolve, reject) {http.get("http://localhost', function(res) {    var bufs = [];    res.on('data', bufs.push.bind(bufs))    .on('end', function() {        var str = Buffer.concat(bufs).toString();        if(str && str[0] === '{') {            var obj = JSON.parse(str);            return resolve(obj.ret);        } else {            return resolve(false);        }    });});});

　　

URL字符的码集

答案 [a-zA-Z0-9] $-_.+!*'(),%

"...Only alphanumerics [0-9a-zA-Z], the special characters "$-_.+!*'(),"

[not including the quotes - ed], and reserved characters used for their

reserved purposes may be used unencoded within a URL."

“只有字母和数字[0-9a-zA-Z]、一些特殊符号“$-_.+!*'(),”

[不包括双引号]、以及某些保留字，才可以不经过编码直接用于URL。”

将随机数编成定长的16进制

Math.floor(Math.random()*0xfffff | 0x100000).toString(16).substr(1)

string.substr(start, length)

string.substring(from, to)

转换十进制成16进制

How to convert decimal to hex in JavaScript?

hexString = yourNumber.toString(16);

yourNumber = parseInt(hexString, 16);

'.'.charCodeAt(0).toString(16)

promise的多个finally和timer间有竞争条件吗

什么意思？

nodejs child_process exit事件和close事件的区别

This event is emitted when the stdio streams of a child process have all terminated. This is distinct from 'exit', since multiple processes might share the same stdio streams.

Spawn时，stdio选项可以是ipc或者stream object，它们是共享的文件描述符。

如何把 %E4%B8%AD 转成汉字

decodeURIComponent('%E4%B8%AD')

创建一个自签名的https服务器

https://cnodejs.org/topic/54745ac22804a0997d38b32d

koa教程

http://koa.rednode.cn/

把string转化成一个stream

var s = new stream.Readable();

s._read = function noop() {}; // redundant? see update below

s.push('your text here');

s.push(null);

把stream转化成一个string，

The key is to use these two Stream events:

Event: 'data'

Event: 'end'

For stream.on('data', ...) you should collect your data data into either a Buffer (if it is binary) or into a string.

For on('end', ...) you should call a callback with you completed buffer, or if you can inline it and use return using a Promises library.

new Function多个参数

http://stackoverflow.com/questions/1606797/use-of-apply-with-new-operator-is-this-possible

var f = new (Function.prototype.bind.apply(Function, [null, 'a', 'b', 'return a*b']));

运行new Cls()时，参数数目是固定的。但是bind方法可以：

var f = Cls.bind(anything, arg1, arg2, ...);

result = new f();

anything是什么没关系，因为new操作重置了f的上下文。只是句法的需要。

现在，对于bind调用，我们要传入可变参数，那就这样：

var f = Cls.bind.apply(Cls, [anything, arg1, arg2, ...]);

result = new f();

Cls.bind是个bind函数，但是Cls.bind可能被覆盖。所以用Function.prototype.bind替换。

eval or new Function

http://dfkaye.github.io/2014/03/14/javascript-eval-and-function-constructor/

eval执行代码是，作用域设在当前执行作用域，可以访问局部变量。

The eval function has access to the global scope, so it can clobber any globals as well. Function shares this problem.

eval可以访问全局作用域，所以它能狠揍（哈哈）任何全局变量。Function不存在这个问题。

new Function不能访问当前作用域。可以访问全局。

new Function是都会修改全局的。狠揍的意思是定义变量不写var前缀。

eval是，如果当前中有，则修改当前的。如果没有则狠揍全局的。