键盘上右下是 slash 右上是 back slash 就好记了

@MC
预防性 block

uuid4

你开心就好

@manfay
莫名击中笑点 2333

有了 ncdu 就再也没用过 du 了

2.7.4..

直接 Redis 解决?

LZ 不好意思要预防性 Block 一下了.

这是一个可以验证 cron 语句的网站: http://crontab.guru/.

如果无法访问请备天梯.

@JhOOOn

* */1 * * * 并不是每小时执行一次. 它跟* * * * * 是一样的.
每小时执行一次应该是 0 * * * *. 准确来说是每小时的第 0 分钟执行.

@JhOOOn
如果你不想多个 cron job 同时执行(上一个没结束下一个就进来了), 这个可以用 lockfile 实现.

最简单的思路:
- 执行时去制定路径检查 pid 文件.
---- 如果 pid 文件不存在
--------- 把当前 pid 写入文件,继续执行
---- 若 pid 文件存在
--------- grep pid, 看进程是否还活着
-------------- 进程不存在, 写入 pid, 继续执行
-------------- 存在, exit 0;

@JhOOOn
http://cron.schlitt.info/index.php?cron=*+*%2F1+*+*+*+&iterations=10&test=Test

@bbx @e1eph4nt
感谢

之前用 ElasticCache 没找到内部实现主从切换(主写从读).. 随手写了下:
https://gist.github.com/PaulLiang1/b145c7219773916bc701

评论褒贬不一啊

```
You're using JS, which helps the expressivity issue a bit, but in exchange it's inheriting all the problems of JS, and squishing them into my web server, and with no apparent framework for making common and dangerous tasks simple and safe.

For example, the comment in your second says that unary + applied to a string will "convert upstream number to integer", but that's not true. It converts a String to a Number (including the "number" NaN). +"0.5" is the Number 0.5, which will send you to the server "my_upstream0.5". +"X" is NaN, which will send you to "my_upstreamNaN". Unary + supports scientific notation, too, so "1.2e-100" becomes "my_upstream1.2e-100". It supports hexadecimal integers, too, though that's less interesting when you clamp to [0,1].

These mis-routings are probably harmless in this case, but it's not hard to imagine similar situations where they're not.

If the authors of a feature can't use it safely in their trivial demo examples in the product announcement, what confidence do I have that I'm going to be able to make it work reliably and securely on an actual production website?

--JS Dude
```