How to find the title for a PDF from the metadata? - powershell

Question

How can I get the title for a PDF file after having renamed the file itself?
PSPath : Microsoft.PowerShell.Core\FileSystem::/home/nicholas/to/99.pdf
PSParentPath : Microsoft.PowerShell.Core\FileSystem::/home/nicholas/to
PSChildName : 99.pdf
PSDrive : /
PSProvider : Microsoft.PowerShell.Core\FileSystem
PSIsContainer : False
Mode : -----
ModeWithoutHardLink : -----
VersionInfo : File: /home/nicholas/to/99.pdf
InternalName:
OriginalFilename:
FileVersion:
FileDescription:
Product:
ProductVersion:
Debug: False
Patched: False
PreRelease: False
PrivateBuild: False
SpecialBuild: False
Language:
BaseName : 99
Target :
LinkType :
Length : 592483
DirectoryName : /home/nicholas/to
Directory : /home/nicholas/to
IsReadOnly : False
FullName : /home/nicholas/to/99.pdf
Extension : .pdf
Name : 99.pdf
Exists : True
CreationTime : 2/19/2021 11:45:18 PM
CreationTimeUtc : 2/20/2021 7:45:18 AM
LastAccessTime : 2/20/2021 2:02:36 AM
LastAccessTimeUtc : 2/20/2021 10:02:36 AM
LastWriteTime : 2/19/2021 11:45:18 PM
LastWriteTimeUtc : 2/20/2021 7:45:18 AM
Attributes : Normal
PS /home/nicholas/to>
PS /home/nicholas/to> Get-ChildItem -Path ./ –File | Select-Object -Property *
This is to bulk import PDF files into calibre, which, notably, seems to recognize duplicates and even displays some titles. Is it parsing the PDF file itself, or gleaning this from meta-data?

Answer 1

For this, you can use pdfinfo.exe which you can find as part of the free Xpdf command line tools.
After you have downloaded and extracted the zip file, copy pdfinfo.exe to some directory and make sure you unblock it, either by right-click or by using PowerShell
Unblock-File -Path 'Where\Ever\You\Have\Copied\It\To\pdfinfo.exe'
Using that, to get the original title as stored in the pdf, you do
$title = ((& 'D:\Test\pdfinfo.exe' 'D:\Test\test.pdf' |
Where-Object { $_ -match '^Title:' }) -split ':', 2)[-1].Trim()