powershell filter csv - powershell

Question

Looking for help on best practice as I am Powershell newbie,
I have a csv file and I would like to filter out every row in the csv except for the rows containing "Not Installed"
I would then like to filter those results against a separate csv files housing a list of computers and also exclude any rows containing a match.
Any help or starting points would be appreciated !

Answer 1

For the first part, you can use Select-String -Notmatch ... e.g.:
$file = "data.csv"
$csv = Get-Content $file
$csv | Select-String -Notmatch 'Not Installed' | Out-File $file -Enc ascii
If your CSV file happens to be Unicode, then remove the "-Enc ascii" part since the default for Out-File is Unicode. As for the second part of your question, you're going to need to be bit more specific. However, you should look at the help on Import-Csv and Export-Csv:
man Import-Csv -full
man Export-Csv -full

Answer 2

get-help *csv*
get-help import-csv -examples
example csv file called test.txt
header1,header2,header3
installed,2,3
not installed,2,3
Import the file into a powershell variable and filter it.
$p = Import-CSV .\test.txt
$p | Where { $_.header1 -eq 'installed'}

Answer 3

Came across this question when trying to work out how to do the same thing myself.
What I came up with as a solution was as follows:
$Filtered = $Table|Select-String -Pattern $ExcludeStrings -NotMatch -SimpleMatch
$FilteredArray = #()
$Filtered.Line | foreach {$split = $_ -split ';';
$tidied = $split -replace '#|{|}|^ ';
$obj = New-Object System.Object
$tidied|foreach {$obj|Add-Member -MemberType NoteProperty -Name ($_.split('=')[0]) -Value ($_.split('=')[1])
}
$FilteredArray += $obj
}
The first line is just showing me filtering the array that I got via Import-CSV to get only the results I wanted.
Unfortunately, this leaves me with a MatchInfo array, with each array being in the following format:
#{Column1=Value1; Column2=Value2; Column3=Value3;}
This does not export back out to CSV nicely at all, as is.
So, I opted to create a new output array ($FilteredArray).
I then piped the Line property of the matchinfo array from Select-String into a foreach loop, and for each line, I split it on the semi-colon, then I remove the #{} chars and any leading spaces.
I then create a new System.Object, then pipe the tidied output into another foreach loop, creating new NotePropertys in the obj, naming them from the current line in the tidied output up to the = character, and the value being the remaining text after the = character.
What I end up with is:
PS C:\Users\Graham> $obj
Column1 : Value1
Column2 : Value2
Column3 : Value3
And the filtered array looks like:
PS C:\Users\Graham> $FilteredArray[0..3]|Format-table
Column1 Column2 Column2
------- ------- -------
Value1 Value2 Value3
Value1 Value2 Value3
Value1 Value2 Value3