param (
	[parameter( Mandatory = $False, ValueFromPipeline = $True )]
	[string] $excelfile,
	[switch] $h,
	[parameter( ValueFromRemainingArguments = $true )]
	[object] $invalidArgs
)

if ( $h -or $invalidArgs -or $excelfile.Contains( "?" ) -or ![System.IO.File]::Exists( $excelfile ) ) {
	if ( ![string]::IsNullOrWhiteSpace( $excelfile ) -and !$excelfile.Contains( "?" ) -and ![System.IO.File]::Exists( $excelfile ) ) {
		Write-Host
		Write-Host "ERROR:   " -ForegroundColor Red -NoNewline
		Write-Host ( "Excel file `"{0}`" not found" -f $excelfile )
	} elseif ( $h -or [bool] $invalidArgs ) {
		Write-Host
		Write-Host "ERROR:   " -ForegroundColor Red -NoNewline
		Write-Host "Too many argument(s)"
	}
	Write-Host
	Write-Host "ReadExcel.ps1,  Version 1.00"
	Write-Host "Read an Excel file and show all cells for all sheets"
	Write-Host
	Write-Host "Usage:   " -NoNewline
	Write-Host "./ReadExcel.ps1  excelfile" -ForegroundColor White
	Write-Host
	Write-Host "Where:   " -NoNewline
	Write-Host "excelfile   " -ForegroundColor White -NoNewline
	Write-Host "is the Excel file to be read"
	Write-Host
	Write-Host "Notes:   This script requires Excel."
	Write-Host "         This script " -NoNewline
	Write-Host "may " -ForegroundColor White -NoNewline
	Write-Host "sometimes leave Excel open after running."
	Write-Host "         Return code (`"errorlevel`") 1 in case of errors, otherwise 0."
	Write-Host
	Write-Host "Credits: Based on article by François-Xavier Cat"
	Write-Host "         https://lazywinadmin.com/2014/03" -ForegroundColor Darkgray
	Write-Host "         /powershell-read-excel-file-using-com.html" -ForegroundColor Darkgray
	Write-Host
	Write-Host "Written by Rob van der Woude"
	Write-Host "https://www.robvanderwoude.com"

	Exit 1
}

$objExcel = New-Object -ComObject Excel.Application
$workbook = $objExcel.Workbooks.Open( $excelfile )
$workbook.Sheets | ForEach-Object {
	if ( ![string]::IsNullOrEmpty( $_.Range( "A1" ).Text ) ) {
		Write-Host $_.Name # sheet name
		Write-Host ( "=" * $_.Name.Length ) # underline sheet name
		for ( $row = 1; $row -le $_.UsedRange.Rows.Count; $row++ ) {
			for ( $column = 1; $column -le $_.UsedRange.Columns.Count ; $column++ ) {
				Write-Host ( "({0}{1})`t{2}" -f ( [char] ( $column + 64 ) ), $row, $_.Columns.Item( $column ).Rows.Item( $row ).Text )
			}
			Write-Host
		}
	}
}

[void] $workbook.Close( )
[void] $objExcel.Quit( )