子字符串的powershell子字符串

Question

I'm trying to substring a substring of a text file in order to cut out the text I need from a text file.

In this example if the file contains the following

this is a test example
second line of text
third line of text

I want to remove everything before second, then get everything between "second" and "third line". So the output would be

second line of text
third line

This is what I have and it works if put a hardcoded length in $second, but I can't get the length correct as a variable:

$text = ( Get-Content -raw Test.txt | Out-String ).Trim() 

$first = $text.IndexOf('second')

$second = $text.Substring($text.IndexOf('second'), ($text.length-1))

$third = $second.Substring(0, $second.IndexOf('third line'))

$text.Substring($first, $third) | Set-Content file2.txt

Answer 1

couple of ways you could do this:

first- specify what you dont want

Get-Content -Path textfile | 
  Where-Object {$_ -NotLike 'this is a*'} | 
    Set-Content file2.txt

second- specify what you do want

Get-Content -Path textfile | 
  Where-Object {$_ -Like 'second*' -or $_ -like 'third*'}  | 
    Set-Content file2.txt

or

Get-Content -Path textfile | 
  Where-Object {$_ -match '^(second|third)'}   | 
    Set-Content file2.txt

Answer 2

Here I was getting text data and then splitting it by single line ( `n ) doing so will make an array of string lines. Then I get strings number by array enumeration [1..2].

PS C:\> $string = @"
this is a test example
second line of text
third line of text
"@

$string.Split("`n")[1..2]
second line of text
third line of text