delete everything after keyword - powershell

Question

I try to merge to files with Compare-Object and I got a file like this:
Number=5
Example=4
Track=1000
Date=07/08/2018 19:51:16
MatCaissierePDAAssoc=
NomImpPDAAssoc=
TpeForceLectPan=0
Number=1
Example=1
Track=0
Date=01/01/1999
You can see it repeats with Number=1. Except with a different value.
I would like to delete everything (everything means not only "= 1") after my keyword "Number" and my keyword itself.
This is what I did so far:
$files = Get-ChildItem "D:\all"
foreach ($file in $files) {
$name = dir $file.FullName | select -ExpandProperty Name
Compare-Object -ReferenceObject (Get-Content D:\original\test.ini) -DifferenceObject (Get-Content $file.FullName) -PassThru |
Out-File ('D:\output\' + $name)
}
And I would like to delete all lines with "Track" and "Date".
My Result should look like this:
Number=5
Example=4
MatCaissierePDAAssoc=
NomImpPDAAssoc=
TpeForceLectPan=0
In fact I need something to delete double keys in my file.

Answer 1

This might help:
# read existing file
$fileContent = Get-Content C:\tmp\so01.txt
# iterate over lines
foreach($line in $fileContent) {
# filter lines beginning with 'Track' or 'Number'
if((-not $line.StartsWith('Track')) -and (-not $line.StartsWith('Number'))) {
# output lines to new file
$line | Add-Content C:\tmp\so02.txt
}
}
Content of C:\tmp\so02.txt:
Example=4
Date=07/08/2018 19:51:16
MatCaissierePDAAssoc=
NomImpPDAAssoc=
TpeForceLectPan=0
Example=1
Date=01/01/1999