如何让 Ruby 脚本每秒运行一次? [英] How do I make a Ruby script run once a second?

问题描述

我有一个需要每秒运行一次的 Ruby 脚本.我正在使用 Ruby 脚本来跟踪目录中文件的修改，并希望该脚本在实时"时间跟踪更新.

I have a Ruby script that needs to run about one time a second. I am using a Ruby script to keep track of modifications of files in a directory and want the script to track updates in "live" time.

基本上，我希望我的脚本执行与在 Unix shell 上运行top"相同的事情，其中​​屏幕大约每秒更新一次.Ruby 中的 setInterval 是否与 JavaScript 中的相同?

Basically, I want my script to do the same kind of thing as running "top" on a Unix shell, where the screen is updated every second or so. Is there an equivalent to setInterval in Ruby like there is in JavaScript?

推荐答案

有几种方法可以做到这一点.

There are a few ways to do this.

快速而肮脏的版本:

1. 贝壳(朝鲜语):

1. shell (kornish):

while :; do
   my_ruby_script.rb
   sleep 1
done

观看(1):

watch(1):

shell$ watch -n 1 my_ruby_script.rb

这将每秒运行您的脚本，并将最近运行的输出显示在您的终端中.

This will run your script every second and keep the output of the most recent run displayed in your terminal.

在红宝石中:

while true
   do_my_stuff
   sleep 1
end

这些都面临着同样的问题:如果实际的脚本/函数需要时间来运行，它会使循环运行的时间少于每秒.

These all suffer from the same issue: if the actual script/function takes time to run, it makes the loop run less than every second.

这是一个 ruby​​ 函数，它可以确保(几乎)每秒准确地调用该函数，只要该函数花费的时间不超过一秒:

Here is a ruby function that will make sure the function is called (almost) exactly every second, as long as the function doesn't take longer than a second:

def secondly_loop
    last = Time.now
    while true
        yield
        now = Time.now
        _next = [last + 1,now].max
        sleep (_next-now)
        last = _next
    end
end

像这样使用它:

secondly_loop { my_function }

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