如何将路径与前五个字符匹配 [英] How to match a path with the first five characters

问题描述

我必须到达位置 / var / log / acpchef / commv123 ，其中 123 可以更改为 456 。

I have to reach the location /var/log/acpchef/commv123, where 123 can change to 456.

我累了 Dir.glob 。我需要 / var / log / acpchef / commv *** 。我的执行将在 mixlibshel​​lout 中。

I tired Dir.glob. I need /var/log/acpchef/commv***. My execution will be in mixlibshellout.

begin
  cwd_kernel = Dir.glob('/var/cache/acpchef/commv***')
  cmd = Mixlib::ShellOut.new("commandrun", :cwd => cwd_kernel)
  cmd.run_command
  log 'run'
end 

推荐答案

这将使文件名与前五个字符以及之后的任何内容匹配：

This will match a filenename with the first five characters and anything after that:

Dir.glob('/var/cache/acpchef/commv*') 
# will match /var/cache/acpchef/commv12345abcdxyz123456

此文件名将与任何三个额外字符相匹配：

This will match a filename with any three extra characters:

Dir.glob('/var/cache/acpchef/commv???') 
# will match /var/cache/acpchef/{commv123, commv456, commvabc, ...}

这将匹配具有三个数字的文件名：

This will match a filename with three numbers:

Dir.glob('/var/cache/acpchef/commv[0-9][0-9][0-9]')
# will match /var/cache/acpchef/commv{123, 234, 456, 999, ...}

此外，您的示例未正确使用块语法，并且开始 ..end 而没有 rescue ，这实际上没有任何作用。它应该变成：

Also, your example is not correctly using the block syntax and has begin..end without rescue, which does essentially nothing. It should become:

Dir.glob('/var/cache/acpchef/commv???').each do |cwd_kernel|
  cmd = Mixlib::ShellOut.new("commandrun", :cwd => cwd_kernel)
  cmd.run_command
  log 'run'
end

Dir.glob 返回数组，它是结果的集合。 Array.each 返回一个枚举器，基本上是一个对象，它以可用的新值运行具有新值的次数的以下代码块，这意味着您可以使用它为所有结果生成相同的代码块 Dir.glob 。该值通过 | block_argument | 语法传递给块。

Dir.glob returns an Array, which is a collection of the results. Array.each returns an Enumerator, which basically is an object that runs the following block of code with a new value as many times as there are new values available, which means you can use it to run the same block of code for all the results of Dir.glob. The value is passed to the block through the |block_argument| syntax.

开始 关键字红宝石中的int用于捕获错误：

The begin keyword in ruby is used to capture errors:

begin
  # do something that generates an exception
rescue => exception
  # handle the exception
end

A 开始而没有救援，确保或其他不执行任何操作。

A begin without rescue, ensure or else does nothing.

此外，这与上一个问题非常相似。

Also, this is quite similar to a previous question.

这篇关于如何将路径与前五个字符匹配的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！