How to use powershell to select range and dump that to csv file - excel

Question

Actually, this is a version of question here:
How to use powershell to select and copy columns and rows in which data is present in new workbook.
The goal is to grab certain columns from multiple Excel workbooks and dump everything to one csv file. Columns are always the same.
I'm doing that manually:
$xl = New-Object -ComObject Excel.Application
$xl.Visible = $false
$xl.DisplayAlerts = $false
$counter = 0
$input_folder = "C:\Users\user\Documents\excelfiles"
$output_folder = "C:\Users\user\Documents\csvdump"
Get-ChildItem $input_folder -File |
Foreach-Object {
$counter++
$wb = $xl.Workbooks.Open($_.FullName, 0, 1, 5, "")
try {
$ws = $wb.Worksheets.item('Calls') # => This specific worksheet
$rowMax = ($ws.UsedRange.Rows).count
for ($i=1; $i -le $rowMax-1; $i++) {
$newRow = New-Object -Type PSObject -Property #{
'Type' = $ws.Cells.Item(1+$i,1).text
'Direction' = $ws.Cells.Item(1+$i,2).text
'From' = $ws.Cells.Item(1+$i,3).text
'To' = $ws.Cells.Item(1+$i,4).text
}
$newRow | Export-Csv -Path $("$output_folder\$ESO_Output") -Append -noType -Force
}
}
} catch {
Write-host "No such workbook" -ForegroundColor Red
# Return
}
}
Question:
This works, but is extremely slow because Excel has to select every cell, copy that, then Powershell has to create array and save row by row in output csv file.
Is there a method to select a range in Excel (number of columns times ($ws.UsedRange.Rows).count), cut header line and just append this range (array?) to csv file to make everything much faster?

Answer 1

So that's the final solution
Script is 22 times faster!!! than original solution.
Hope somebody will find that useful :)
PasteSpecial is to filter out empty rows. There is no need to save them into csv
$xl = New-Object -ComObject Excel.Application
$xl.Visible = $false
$xl.DisplayAlerts = $false
$counter = 0
$input_folder = "C:\Users\user\Documents\excelfiles"
$output_folder = "C:\Users\user\Documents\csvdump"
Get-ChildItem $input_folder -File |
Foreach-Object {
$counter++
try {
$new_ws1 = $wb.Worksheets.add()
$ws = $wb.Worksheets.item('Calls')
$rowMax = ($ws.UsedRange.Rows).count
$range = $ws.Range("A1:O$rowMax")
$x = $range.copy()
$y = $new_ws1.Range("A1:O$rowMax").PasteSpecial([System.Type]::Missing,[System.Type]::Missing,$true,$false)
$wb.SaveAs("$($output_folder)\$($_.Basename)",[Microsoft.Office.Interop.Excel.XlFileFormat]::xlCSVWindows)
} catch {
Write-host "No such workbook" -ForegroundColor Red
# Return
}
}
$xl.Quit()
Part above will generate a bunch of csv files.
Part below will read these files in separate loop and combine them together into one.
-exclude is an array of something I want to omit
Remove-Item to remove temporary files
Answer below is based on this post: https://stackoverflow.com/a/27893253/6190661
$getFirstLine = $true
Get-ChildItem "$output_folder\*.csv" -exclude $excluded | foreach {
$filePath = $_
$lines = Get-Content $filePath
$linesToWrite = switch($getFirstLine) {
$true {$lines}
$false {$lines | Select -Skip 1}
}
$getFirstLine = $false
Add-Content "$($output_folder)\MERGED_CSV_FILE.csv" $linesToWrite
Remove-Item $_.FullName
}