Extracting text from word documents - powershell

Question

TASK
Extract text from .doc, .docx and .pdf files and upload content to an Azure SQL database. Needs to be fast as its running over millions of documents.
ISSUES
Script starts to fail if one of the documents has an issue. Some that i have come across are:
This file failed to open last time you tried - Open readonly
File is corrupt
SCRIPT
Firstly i generate a list of files containing 100 file paths. This is so i can continue execution if i need to stop it and / or it errors out:
## Word object
if (!($continue)) {
$files = (Get-ChildItem -force -recurse $documentFolder -include *.doc, *.docx).fullname
$files | Out-File (Join-Path $PSScriptRoot "\documents.txt")
$i=0; Get-Content $documentFile -ReadCount 100 | %{$i++; $_ | Out-File (Join-Path $PSScriptRoot "\FileLists\documents_$i.txt")}
}
Then i create the ComObject with the DisplayAlerts flag set to 0 (i thought this would fix it. It didnt)
$word = New-Object -ComObject word.application
$word.Visible = $false
$saveFormat = [Enum]::Parse([Microsoft.Office.Interop.Word.WdSaveFormat], "wdFormatText")
$word.DisplayAlerts = 0
After this, I loop through each file in each list, save the file as .txt to the temp folder, extract the text and generate an SQL INSERT statemnt:
foreach ($file in (Get-Content $list)) {
Try {
if ($file -like "*-*") {
Write-Output "Processing: $($file)"
$doc = $word.Documents.Open($file)
$fileName = [io.path]::GetFileNameWithoutExtension($file)
$fileName = $filename + ".txt"
$doc.SaveAs("$env:TEMP\$fileName", [ref]$saveFormat)
$doc.Close()
$4ID = $fileName.split('-')[-1].replace(' ', '').replace(".txt", "")
$text = Get-Content -raw "$env:TEMP\$fileName"
$text = $text.replace("'", "")
$query += "
('$text', $4ID),"
Remove-Item -Force "$env:TEMP\$fileName"
}
<# Upload to azure #>
$query = $query.Substring(0,$query.Length-1)
$query += ";"
$params = #{
'Database' = $TRIS5DATABASENAME
'ServerInstance' = $($AzureServerInstance.FullyQualifiedDomainName)
'Username' = $AdminLogin
'Password' = $InsecurePassword
'query' = $query
}
Invoke-Sqlcmd #params -ErrorAction "continue"
$query = "INSERT INTO tmp_CachedText (tCachedText, tOID)
VALUES "
}
Catch {
Write-Host "$($file) failed to process" -ForegroundColor RED;
}
}
Remove-Item -Force $list.FullName
ISSUES
As stated above, if something is wrong with one of the files or the document failed to open properly off a previous run the script starts failing. Everything in the loop throws errors, starting with:
You cannot call a method on a null-valued expression.
At D:\OneDrive\Scripts\Microsoft Cloud\CachedText-Extraction\CachedText-Extraction.ps1:226 char:13
+ $doc = $word.Documents.Open($file)
Basically what i want is a way to stop those errors from appearing by simply skipping the file if it has an error with the document. Alternatively, if there is a better way to extract text from document files using PowerShell and not using word that would be good too.
An example of one of the error messages:
This causes the file to be locked and execution to pause. The only way to get around it is to kill word, which then causes the rest of the script to fail.