PDFMtEd

PDFMtEd (PDF Metadata Editor) is a set of tools designed to simplify working with PDF metadata on Linux. The utilities hosted in this repository are graphical front-ends to the marvelous ExifTool by Phil Harvey.

Table of contents

• Components
  • PDFMtEd Editor
  • PDFMtEd Inspector
  • PDFMtEd Thumbnailer
• Installation and dependencies
  • Dependencies
    • Ubuntu 16.04 or lower
    • Most other Linux distribution based on Debian or Ubuntu
    • Fedora and most other Linux distribution based on Fedora
    • Arch Linux or Manjaro
    • Dependency breakdown
  • Installation
  • Uninstall PDFMtEd
• Usage
  • General usage
  • PDFMtEd Editor
    • User interface
    • Command-line options
  • PDFMtEd Inspector
  • PDFMtEd Thumbnailer
• Additional information
  • Modified metadata tags
  • Purging metadata
• Known issues
• License

Components

PDFMtEd Editor

Overview

PDFMtEd Editor is an easy-to-use graphical metadata editor that supports viewing and modifying all major metadata fields found in PDF documents.

Screenshot

Features:

• easily process multiple files and folders right from your file manager
• preview your documents in your default PDF viewer and file manager before editing them
• rename files based on metadata

PDFMtEd Inspector

Overview

PDFMtEd Inspector is a general purpose metadata viewer and cleaner. Aside from granting a quick and easy insight into the meta information stored in your files, it also allows you to quickly and effectively purge all metadata.

While it can handle all file formats supported by exiftool, PDFMtEd Inspector was primarily designed with PDF files in mind.

Screenshot

Features:

• quickly inspect metadata right from your file manager
• easily purge single or multiple files of all metadata

PDFMtEd Thumbnailer

Overview

PDFMtEd Thumbnailer provides the thumbnail previews for the utilities hosted in this repository. It also acts as a general purpose thumbnailing script that can recursively generate thumbnails for one or more directories.

PDFMtEd Thumbnailer should be able to generate thumbnails for all file types supported by Nautilus/GNOME's thumbnailing back-end.

Note: pdfmted-thumbnailer was written by James Henstridge as part of an AskUbuntu Q&A.

Installation and dependencies

The following instructions are provided for most Linux distributions.

Dependencies

Optional but recommended: sejda-console

Ubuntu 16.04 or lower

Install all dependencies on Ubuntu with the following commands:

sudo add-apt-repository ppa:webupd8team/y-ppa-manager
sudo apt-get update
sudo apt-get install yad libimage-exiftool-perl qpdf

Most other Linux distribution based on Debian or Ubuntu

sudo apt install libimage-exiftool-perl yad qpdf

Fedora and most other Linux distribution based on Fedora

sudo dnf install perl-Image-ExifTool yad qpdf

Arch Linux or Manjaro

sudo pacman -S perl-image-exiftool yad qpdf

Dependency breakdown

Required:

• YAD: graphical front-end for bash scripts, a Zenity fork; provided by Webupd8 PPA
• ExifTool: general purpose metadata editing application and library
• qpdf: command-line program that does structural, content-preserving transformations on PDF files; used in this project to restore broken PDF files and purge documents of residual metadata
• Python 3 is required for the thumbnailer and thumbnail preview to work. This should be installed on your system by default.

Recommended:

• Sejda: extensible and configurable PDF manipulation layer library; used to restore broken PDF files; more reliable than qpdf in this, but unfortunately not available in any repository; please use the debfile release to install sejda-console

Installation

1. Install all dependencies

2. Clone this repository or download the latest zipfile and extract it

3. cd to the cloned/extracted directory, e.g.:

    cd PDFMtEd
   

4. Run the provided installer:

    sudo ./install.sh
   

   (If your file manager supports custom scripts you can just copy the PDFMtEd folder to the default scripts path instead (instructions for Nautilus))

After the installation PDFMtEd Editor and Inspector should be available as entries in the Open with context menu:

If you can't find the entries click on Other application (arrow) and navigate to Show other applications. You should be able to find the PDFMtEd launchers in the list. Double-click on PDFMtEd Inspector to open the application. This will automatically add a context menu entry. Repeat the procedure for PDFMtEd Editor and you are set.

Uninstall PDFMtEd

Follow these steps to uninstall the PDFMted utilities:

1. cd to the project directory, e.g.:

    cd PDFMtEd
   

2. Run uninstall.sh as root:

    sudo ./uninstall.sh
   

Usage

General usage

1. Use your file manager to select one or more files/directories
2. Choose the utility you want to launch from the Open with context menu

PDFMtEd Editor

Important note: All changes introduced by ExifTool, and in turn PDFMtEd Editor, are potentially reversible, which might be a security issue under some circumstances.

PDFMtEd Inspector (not the Editor!) works around this by using qpdf to purge PDF files of all existing metadata (further reading: Purging metadata).

User interface

Here are some helpful pointers:

• you can use the next/previous buttons to navigate between files

• you can transfer metadata to the next file by selecting Copy tags over to next/previous file option

• renamed files follow this naming scheme: ${AUTHOR} - ${TITLE} - ${YEAR}

  You can change the scheme by modifying the update_filename function in pdfmted-editor (I haven't implemented a proper setting for this, yet)

• exiftool will sometimes fail at updating the metadata of a document. In most cases this is because the PDF file is malformatted. PDFMtEd automatically detects these errors and prompts you to try to repair the file via qpdf or sejda-console. Personally, I've had more success with Sejda than qpdf, so I'd recommend choosing that option if you are able to install sejda-console.

Command-line options

There are a couple of command-line switches that might be interesting:

• -r will instruct PDFMtEd Editor to check the rename option by default
• -u enables parsing of URIs instead of file paths

PDFMtEd Inspector

The UI should be self-explanatory.

PDFMtEd Thumbnailer

Call pdfmted-thumbnailer from the command-line to generate thumbnails:

pdfmted-thumbnailer <file(s) or folder(s)>

E.g.:

pdfmted-thumbnailer "file.pdf" "/home/user/Documents" "file2.pdf"

This would generate thumbnails for file.pdf, file2.pdf, and all compatible files found under /home/user/Documents and all of its sub-folders.

Additional information

Modified metadata tags

PDF documents use a variety of different metadata formats to store meta information.

The oldest and most common tag system is the PDF Info dictionary. This is the metadata system CLI tools like pdfinfo or the Properties dialog of various GNOME applications parse.

PDF editors like Adobe Acrobat additionally use the more recent XMP metadata format.

To avert confusion and ensure consistency across different PDF handlers it is important to keep these two metadata systems synchronized. That's why each field in PDFMtEd Editor's user interface controls two separate metadata tags:

UI field	PDF Info dictionary entry	corresponding XMP Dublin Core namespace tag
Author	Author	Creator
Title	Title	Title
Year	CreateDate	Date
Keywords	Keywords	Subject
Subject	Subject	Description

Purging metadata

Removing PDF metadata is not as straightforward as you might think. As stated before, exiftool operations are reversible, so removing all PDF tags with exiftool -all:all="" is no good on its own.

Only by rebuilding the PDF file (e.g. with qpdf) we can ensure that all orphan data is purged irreversibly.

Note: This method does not remove metadata included in embedded objects (e.g. images, vector graphics). To see if your file contains any residual metadata entries you could use a tool like strings that can look for printable strings in binary data such as PDF files.

Known issues

• the Webupd8 PPA currently hosts a GTK2 version of YAD. This build is affected by a bug that prevents text labels from aligning properly. As a result, the UI might look somewhat disjointed.

  If you don't want to wait for a fix you can directly compile the YAD GTK3 build from source. Provided your system satisfies all dependencies mentioned on the YAD project page, you may compile and install YAD with the following routine:

    svn checkout svn://svn.code.sf.net/p/yad-dialog/code/trunk yad-dialog-code
    cd yad-dialog-code
    autoreconf -v -i
    ./configure --with-gtk=gtk3
    make
    sudo make install
  

License

PDFMtEd copyright 2014 Glutanimate

PDFMtEd is licensed under the GNU GPLv3.