How to extract specific tables from html file using native powershell commands?

Question

I make use of the PAL tool (https://pal.codeplex.com/) to generate HTML reports from perfmon logs within Windows. After PAL processes .blg files from perfmon it dumps the in

Answer 1

OK, this isn't thoroughly tested but works with your example table in PS 2.0 with IE11:

# Parsing HTML with IE.
$oIE = New-Object -ComObject InternetExplorer.Application
$oIE.Navigate("file.html")
$oHtmlDoc = $oIE.Document

# Getting table by ID.
$oTable = $oHtmlDoc.getElementByID("table6")

# Extracting table rows as a collection.
$oTbody = $oTable.childNodes | Where-Object { $_.tagName -eq "tbody" }
$cTrs = $oTbody.childNodes | Where-Object { $_.tagName -eq "tr" }

# Creating a collection of table headers.
$cThs = $cTrs[0].childNodes | Where-Object { $_.tagName -eq "th" }
$cHeaders = @()
foreach ($oTh in $cThs) {
    $cHeaders += `
        ($oTh.childNodes | Where-Object { $_.tagName -eq "b" }).innerHTML
}

# Converting rows to a collection of PS objects exportable to CSV.
$cCsv = @()
foreach ($oTr in $cTrs) {
    $cTds = $oTr.childNodes | Where-Object { $_.tagName -eq "td" }
    # Skipping the first row (headers).
    if ([String]::IsNullOrEmpty($cTds)) { continue }
    $oRow = New-Object PSObject
    for ($i = 0; $i -lt $cHeaders.Count; $i++) {
        $oRow | Add-Member -MemberType NoteProperty -Name $cHeaders[$i] `
            -Value $cTds[$i].innerHTML
    }
    $cCsv += $oRow
}

# Closing IE.
$oIE.Quit()

# Exporting CSV.
$cCsv | Export-Csv -Path "file.csv" -NoTypeInformation

Honestly, I didn't aim for optimal code. It's just an example of how you could work with DOM objects in PS and convert them to PS objects.

Answer 2

I see you accepted an answer but I thought I'd add a RegEx solution in here too. No COM objects needed for this one, and should be PSv2 friendly I'm pretty sure.

$Path = 'C:\Path\To\File.html'
[regex]$regex = "(?s)<TABLE ID=.*?</TABLE>"
$tables = $regex.matches((GC C:\Temp\test.txt -raw)).groups.value
ForEach($String in $tables){
    $table = $string.split("`n")
    $CurTable = @()
    $CurTableName = ([regex]'TABLE ID="([^"]*)"').matches($table[0]).groups[1].value
    $CurTable += ($table[1] -replace "</B></TH><TH><B>",",") -replace "</?(TR|TH|B)>"
    $CurTable += $table[2..($table.count-2)]|ForEach{$_ -replace "</TD><TD>","," -replace "</?T(D|R)>"}
    $CurTable | convertfrom-csv | export-csv "C:\Path\To\Output\$CurTableName.csv" -notype
}

That should output a CSV file for each table found. Such as table6.csv, table9.csv etc. If you wanted to output CSVs per HTML file you could wrap the entire thing in a ForEach loop like:

ForEach($File in (Get-ChildItem "$Path\*.html")){
    Insert above code here
}

You would need to modify the $tables = line so that it was GC $file.fullname to that it would load up each file as it iterated through.

Then just modify the Export-Csv to something like:

$CurTable | convertfrom-csv | export-csv "C:\Path\To\Output\$($File.BaseName)\$CurTableName.csv" -notype

So if you had Server01.html with 3 tables in it you would get a folder named Server01 with 3 CSV files in it, one for each table.