Powershell Export-Csv creates empty files

Question

I am trying to remove columns from a lot of CSVs at once with Powershell. I'm trying to use

Get Child-Item *.csv | Foreach-Object {Import-Csv $_ | select data, close | Export-Csv $_ - NoTypeInformation}

However, I just end up with a bunch of empty CSVs. I'm guessing this has something to do with exporting a CSV of the same name as what I'm importing because it works fine if I use different names (i.e. Import-Csv X.csv ... Export-Csv XXXXXX.csv).

However, I couldn't figure out how to edit the output CSV names either when I have the '$_' involved and there is too many to do manually.

What is wrong with the command I am giving? Also, for future reference, how would I have the output be a different file name?

Thank you.

Answer 1

OK, one liners are great and all but if you start having issues it might be time to break it down. This will import it to a variable, then select the two columns that you want and export it to a file with -trimmed tacked on the end of the file name.

Gci *.csv ¦ select -expand Fullname ¦ %{
    $current = import-csv $_
    $newname = $_ -replace ".Csv$", "-trimmed.csv"
    $current ¦ select data, close ¦ export-csv $newname -notype

}

That should work, though I am unable to test since I'm posting from my phone while riding the bus on my commute home from work.