使用 PowerShell 拆分字符串并对每个令牌执行某些操作 [英] Split string with PowerShell and do something with each token

问题描述

我想在空格上分割管道的每一行，然后在自己的行上打印每个标记.

I want to split each line of a pipe on spaces, and then print each token on its own line.

我意识到我可以使用以下方法得到这个结果:

I realise that I can get this result using:

(cat someFileInsteadOfAPipe).split(" ")

但我想要更大的灵活性.我希望能够对每个令牌做任何事情.(我曾经在 Unix 上使用 AWK，我正在尝试获得相同的功能.)

But I want more flexibility. I want to be able to do just about anything with each token. (I used to use AWK on Unix, and I'm trying to get the same functionality.)

我目前拥有:

echo "Once upon a time there were three little pigs" | %{$data = $_.split(" "); Write-Output "$($data[0]) and whatever I want to output with it"}

很明显，它只打印第一个标记.有没有办法让我对每个令牌依次打印每个令牌?

Which, obviously, only prints the first token. Is there a way for me to for-each over the tokens, printing each in turn?

另外，%{$data = $_.split(" ");Write-Output "$($data[0])"} 部分我从博客中得到的，我真的不明白我在做什么或语法是如何工作的.

Also, the %{$data = $_.split(" "); Write-Output "$($data[0])"} part I got from a blog, and I really don't understand what I'm doing or how the syntax works.

我想用谷歌搜索它，但我不知道该怎么称呼它.请帮我一两句话到谷歌，或者一个链接向我解释 % 和所有 $ 符号的作用，以及开头的意义和右括号.

I want to google for it, but I don't know what to call it. Please help me out with a word or two to Google, or a link explaining to me what the % and all the $ symbols do, as well as the significance of the opening and closing brackets.

我意识到我实际上不能使用 (cat someFileInsteadOfAPipe).split(" ")，因为文件(或更好的输入管道)包含不止一行.

I realise I can't actually use (cat someFileInsteadOfAPipe).split(" "), since the file (or preferable incoming pipe) contains more than one line.

关于一些答案:

如果您使用 Select-String 来过滤在标记化之前的输出，您需要记住 Select-String 命令的输出不是字符串的集合，而是 MatchInfo 对象的集合.要获得要拆分的字符串，您需要访问 MatchInfo 对象的 Line 属性，如下所示:

If you are using Select-String to filter the output before tokenizing, you need to keep in mind that the output of the Select-String command is not a collection of strings, but a collection of MatchInfo objects. To get to the string you want to split, you need to access the Line property of the MatchInfo object, like so:

cat someFile | Select-String "keywordFoo" | %{$_.Line.Split(" ")}

推荐答案

"Once upon a time there were three little pigs".Split(" ") | ForEach {
    "$_ is a token"
 }

键是$_，代表管道中的当前变量.

The key is $_, which stands for the current variable in the pipeline.

关于您在网上找到的代码:

About the code you found online:

% 是 ForEach 的别名-对象.括号内的任何内容都对其接收到的每个对象运行一次.在这种情况下，它只运行一次，因为您发送的是单个字符串.

% is an alias for ForEach-Object. Anything enclosed inside the brackets is run once for each object it receives. In this case, it's only running once, because you're sending it a single string.

$_.Split(" ") 正在获取当前变量并将其拆分为空格.当前变量将是 ForEach 当前正在循环的任何内容.

$_.Split(" ") is taking the current variable and splitting it on spaces. The current variable will be whatever is currently being looped over by ForEach.

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