Powershell remove two line before a match of string - powershell

Question

I have file.txt that has content like this with empty line in between:
TESTING CONNECTION TO SERVER 1.1.1.1
COULD NOT CONNECT TO SERVER
TESTING CONNECTION TO SERVER 1.2.111.11
CONNECTION TO SERVER SUCCESSFUL
TESTING CONNECTION TO SERVER 12.1.1211.1
COULD NOT CONNECT TO SERVER
The main aim is to remove the IP address or its line from the file which are not able to connect. If the string matches like 'COULD NOT CONNECT' then the ip address or its line before has to be removed using PowerShell script.
$data = foreach($line in Get-Content $env:TEMP\file.txt)
{
if($line -like '*COULD NOT CONNECT*')
{
$linenumber = Get-Content $env:TEMP\file.txt | select-string 'COULD NOT CONNECT' | Select-Object LineNumber
$b = 2
foreach($lines in $linenumber
$lineno=$lines.LineNumber - $b
write-host $lineno
#logic 1
$content = Get-Content $env:TEMP\file.txt
$content | Skip -Index $lineno > $env:TEMP\OUTPUT_refined.txt
#logic 2
Get-Content $env:TEMP\file.txt |
Where-Object ReadCount -ne $lineno |
Set-Content -Encoding Utf8 $env:TEMP\file.txt -Force
#logic 3
$file = "$env:TEMP\file.txt"
$outFile = [IO.File]::CreateText("$env:TEMP\OUTPUT_refined.txt")
$lineNo = 0
try {
foreach ($line in [IO.File]::ReadLines("$env:TEMP\file.txt")) {
if (++$lineNo -eq $lineno) { continue }
$outFile.WriteLine($line)
}
} finally {
$outFile.Dispose()
}
}
}
else
{
$line
}
}
$data | Set-Content $env:TEMP\file.txt -Force
Try attempts with various logics based on calculating line numbers and creating new file with refined content.
After removing the contents either I need it can be same file or we can use Set-Content and create a new file anything is fine. Experts help needed. Thanks.

Answer 1

this code removes the 3 lines: i am using directly the regex of C#
$data = Get-Content -Path file.txt - raw
#select multiline option for regex ->
# so you can work with `r`n (line of feed, new line)
$option = [System.Text.RegularExpressions.RegexOptions]::Multiline
$pattern = [regex]::new("TESTING.+?`r?`n`r?`nCOULD NOT CONNECT.+?`r?`n", $option)
$data = $pattern.Replace($data, "")
$data | Set-Content -Path newfile.txt -Force
TESTING.+?`r?`n`r?`nCOULD NOT CONNECT.+?`r?`n
i am searching all lines beginning by TESTING and finishing by 2 Endoflines (following the text editor endofline is 'r'n or 'n so 'r? means 0 or 1 occurence) and following by COULD NOT CONNECT then end of this line.
that is the selection of 3 lines