Overwriting CSV in PowerShell

I have a CSV document that is of the following structure

Headers

Path,Publish,Hashlist,Package

Content Entries

C:\packages\word.docx, 10:14:17 on 17-08-2011, C:\packages\word.hash, C:\packages\word.zip

Now, I will have multiple lines of entries, but I only want to maintain one entry per path at a given time. So when I add a new entry for C:\packages\word.docx, I want to find and delete the line above. I can append the .CSV no problem in PowerShell, but am unsure how to identify the line base开发者_StackOverflow中文版d on the filepath, and remove/overwrite it.

Something like this maybe:

$csv = import-csv test.csv
$tobeupdated = $csv | ?{$_.Path -eq "pathyouarecurrentlyprocessing"}
if($tobeupdated){
    #update
    $tobeupdated.Publish = "blah blah"

} else{
    #add new
    $tobeupdated = New-Object Object 
    $tobeupdated | Add-Member -type NoteProperty -name Path -value "c:\something.docx"
    $tobeupdated | Add-Member -type NoteProperty -name Publish -value "10:14:17 on 17-08-2011"
    $tobeupdated | Add-Member -type NoteProperty -name Hashlist -value "C:\packages\word.hash"
    $tobeupdated | Add-Member -type NoteProperty -name Package -value "C:\packages\word.zip"
    $csv += $tobeupdated
}

$csv | export-csv test.csv -notype

The update part maybe tricky based on what you are doing. So it will be helpful if you give some code on what you are doing.

This is what I use for updating CSV files. One nice thing about it is that all of the CSV entries don't need to be filtered for every record added/updated. It uses a HashTable to store the collection of CSV records.

function Update-MyCSV {
    param(
        [parameter(ValueFromPipeline=$true)]
        $entry,
        $csvPath
    )
    begin {
        $csv = @{}
        if(Test-Path $csvPath) {
            # Import CSV and add to a HashTable
            Import-Csv -Path $csvPath | foreach {$csv["$($_.Path)"] = $_}
        }
    }
    process {
        # Replaces existing entries and adds nonexisting
        $csv[$entry.Path] = $entry
    }
    end {
        # Export to CSV
        $csv.Values | Export-Csv -Path C:\temp\my.csv -NoTypeInformation
    }
}

function New-CsvEntry {
    param(
        $path,
        $publish,
        $hashlist,
        $package
    )
    New-Object Object|
        Add-Member -type NoteProperty -Name Path -Value $path -PassThru |
        Add-Member -type NoteProperty -Name Publish -value $publish -PassThru |
        Add-Member -type NoteProperty -Name Hashlist -value $hashlist -PassThru |
        Add-Member -type NoteProperty -Name Package -value $package -PassThru
}

# Create new CSV
$entries = @(0..9| foreach {New-CsvEntry "C:\packages\word$_.docx" "10:14:1$_ on 17-08-2011" "C:\packages\word$_.hash" "C:\packages\word$_.zip"})
$entries| Update-MyCSV -csvPath C:\temp\my.csv

# Update some CSV records, and create some new
$newEntries = @(7..12| foreach {New-CsvEntry "C:\packages\word$_.docx" "10:14:1$_ on 17-08-2011" "C:\packages\new$_.hash" "C:\packages\new$_.zip"})
$newEntries| Update-MyCSV -csvPath C:\temp\my.csv