Naive Excel PowerShell Reader Implementation

If possible, use the module at Import Excel. It'll consider more edge cases.

I wrote this to handle a simple read of somewhat well-formed data in an Excel document like below. It has only been tested in a Windows environment without significant edge-cases considered.

SheetInventory

ID	Title	MyDate	Quantity
1	Red Item	3/15/2025 07:00	3
2	Green Item	3/15/2025 07:00	2
3	Blue Item
4	Purple Item	3/15/2025 07:00	22

Date fields are recognized by the format in the spreadsheet. The underlying OpenXML format stores values as numbers.

The script considers multiple sheets as well.

The script only reads files and stores them into a PSCustom Object. Usage might be something like below:

Usage

$content = Grab-ExcelContent "C:\Temp\myExcelDoc.xlsx"
$sheetInventory = $content.sheetInventory
$sheetInventory | Where-Object { $_.Quantity -GT 10 }

My Code

You should be able to be able to copy and paste the following into your own script.

function Grab-ExcelContent($path){
    function Grab-Col($range){
        $col = ($range -split '[0-9]')[0]
        return $col
    }

    function Grab-Row($range){
        $col = ($range -split '[0-9]')[0]
        $row = $range -replace $col,""
        return $row 
    }

    function Grab-Xml($file){
        $stream = $file.Open() 
        $reader = $reader = New-Object IO.StreamReader($stream)
        $text = $reader.ReadToEnd()
        $content = [xml]$text
            $stream.Close()
            $reader.Close() 
        return $content
    }

    $base_date = (Get-Date "1/1/1900").AddDays(-2)
    function Grab-CellValue($cell){
       
        $v = $cell.v
        If($cell.t -eq "s"){
            $ss = $sharedStrings[$v].t
            If($ss."#text" -eq $null){
                return $ss
            } else {
                $ss."#text"
            } 
        } else {
            If($cell.s -ne $null){
                $xf = $xfs[$cell.s]
                $nmid = [int] $xf.numfmtid
                if($nmid -ge 14 -and $nmid -le 22){
                    return $base_date.AddDays($v)
                } else {
                    return $v
                }   
            } else { 
                return $v
            }
        }
    }
    try{
        Add-Type -Assembly "System.IO.Compression.FileSystem"
        $zip = [IO.Compression.ZipFile]::OpenRead($path)
        $sharedStringsFile = $zip.Entries | where FullName -EQ "xl/sharedStrings.xml" 
        $sharedStrings = (Grab-Xml $sharedStringsFile).sst.si
        $worksheets = $zip.Entries | where FullName -Like "xl/worksheets/*" 
        $workbook = Grab-Xml ($zip.Entries | Where FullName -EQ "xl/workbook.xml")
        $styles = Grab-Xml ($zip.Entries | Where FullName -EQ "xl/styles.xml")
        $xfs = $styles.stylesheet.cellXfs.xf
        
    } catch{
        return [pscustomobject]@{"error"="File is likely in use"}
    }
    $wsi = 0
    $content = $worksheets | foreach {
        $sheetData = (Grab-Xml $_).worksheet.sheetData
        $headers = $sheetData.row[0].c | ForEach {      
            $v = Grab-CellValue $_ 
            $c = Grab-Col $_.r
            @{$c=$v}
        }
        $rix = 0 
        $sheet = $sheetData.row | foreach {
            if($rix -eq 0) { $rix++ } else{
                $row = [PSCustomObject]@{}
                $_.c | foreach {
                    $col = Grab-Col $_.r
                    $h = $headers.$col
                    $v = Grab-CellValue $_
                    $row | Add-Member -Name $h -Type NoteProperty -Value $v
                }
                Write-Output $row
            }
        }

        if($worksheets.count -eq 1) {
            $name = $workbook.workbook.sheets.sheet.name
        } else {
            $name = $workbook.workbook.sheets.sheet[$wsi].name
            $wsi++
        } 
        Write-Output ([pscustomobject]@{$name=$sheet})
    }
    $zip.Dispose() 
    return $content
}

dennythecoder/Naive Excel PowerShell Reader.md

Usage

My Code