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I need a command line tool for editing metadata of pdf-files.

I'm using a Aiptek MyNote Premium tablet for writing my notes and minutes on this device, import them later and convert them to pdf automatically with a simple script using inkscape and ghostscript.

Is there any command line tool to add some categories to the pdf's metadata, so i can find the pdf later (e.g. with gnome-do) by categories?

Update: I tried the solution with pdftk and it works, but it seems that gnome-do doesn't take care of pdf-metadata. Is there a way to get gnome-do to do that?

122

Give exiftool a try, it is available from the package libimage-exiftool-perl in the repositories.

As an example, If you have a pdf file called drawing.pdf and you want to update its metadata, Use the utility, exiftool, in this way:

exiftool -Title="This is the Title" -Author="Happy Man" -Subject="PDF Metadata" drawing.pdf

For some reason the Subject entered ends up in the keywords field of the metadata in the pdf file. not a problem in some cases, even desirable, however, this may be problematic, evince and the nautilus metadata previewer do not show this but Adobe Acrobat viewer and PDF-XChange viewer does.

The program will create a backup of the original file if you do not use the; -overwrite_original switch, this means a duplicate will exist in the folder where the updated pdf is. From example above; a file named ; drawing.pdf_original will be created.

use the overwrite switch at your own risk, my suggestion is not to use it and script something to move this file to a better location just in case.

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    Note that: "All metadata edits are reversible. While this would normally be considered an advantage, it is a potential security problem because old information is never actually deleted from the file." – nutty about natty Aug 12 '14 at 7:11
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    @nuttyaboutnatty if you want to purge all remnant and unused metadata entries, you can linearize the PDF file right after processing it with exiftool. This is described in more detail in this Github gist. – Glutanimate Aug 13 '14 at 23:41
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    @nuttyaboutnatty Well, of course it's not an authoritative source but that's only because nobody ever took the time to write one. However, I can assure that the method described by the author works. Try it out yourself: 1.) Take a PDF that has some tags and "delete" all metadata with exiftool -overwrite_original -all:all="" file.pdf; 2.) Use exiftool -PDF-update:all= file.pdf to confirm that there is still old metadata present; 3.) linearize the file with qpdf --linearize file.pdf; 4.) Check again, like you did in 2.); all metadata should be gone; – Glutanimate Aug 14 '14 at 7:54
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    5.) confirm that the file has been purged of all metadata by looking at the PDF dictionary (pdfinfo -meta file.pdf) – Glutanimate Aug 14 '14 at 7:55
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    Works perfectly. I regularly want to copy the metadata from one PDF to another, in which case exiftool -overwrite_original -tagsFromFile <srcfile> <destfile> is what I need (the option -overwrite_original overwrites the original <destfile>). – AstroFloyd Apr 22 '18 at 15:57
17

You can edit metadata by using pdftk. Check out update_info parameter. As for data file, below is an example:

InfoKey: Title
InfoValue: Mt-Djing: multitouch DJ table
InfoKey: Subject
InfoValue: Dissertation for Master degree
InfoKey: Keywords
InfoValue: DJing, NUI, multitouch, user-centered design
InfoKey: Author
InfoValue: Pedro Lopes

(Source)

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    Ok, this means i have to export the metadata to a textfile, edit them and reimport the textfile. Is there a way to directly set a single metadata from command-line? – bdr529 Feb 22 '11 at 6:48
  • There may be, but I couldn't find it. – Olli Feb 22 '11 at 7:26
  • pdftk seems to Unicode characters in the metadata. – Mechanical snail Apr 21 '13 at 21:06
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    I had some problem using pdftk on new pdfs (newer versions are encrypted via AESV2). Seems like it's discontinued. exiftool was working better. – s1lv3r Aug 26 '13 at 14:58
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    to use pdftk, what you need to do is: 1) pdftk book.pdf dump_data output report.txt 2) edit report.txt 3) pdftk book.pdf update_info report.txt output bookcopy.pdf – craq Oct 24 '17 at 3:02
9

Using Ghostview

Install ghostscript with:

$ sudo apt install ghostscript

Create a file named pdfmarks with similar content:

[ /Title (Document title)
  /Author (Author name)
  /Subject (Subject description)
  /Keywords (comma, separated, keywords)
  /ModDate (D:20061204092842)
  /CreationDate (D:20061204092842)
  /Creator (application name or creator note)
  /Producer (PDF producer name or note)
  /DOCINFO pdfmark

then combine this pdfmarks file with a PDF, PS or EPS input file:

gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=output.pdf original.pdf pdfmarks

Source: http://milan.kupcevic.net/ghostscript-ps-pdf/

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4

To elaborate on the pdftk method, which is nice because it shows you everything that's being set, at the same time as allowing you to change anything you like, here is a script (for your .bashrc or other aliases file) to do it with one command. This creates a new version of the file you want to edit, opens your favourite editor with the metadatafile, and then implements your changes and sets the file creation/modification time on the modified PDF file to be the same as the original. To use it, after resourcing your .bashrc file, just type

editPDFmetadata myfile.pdf

Here's the alias:

editPDFmetadata() {
OUTPUT="${1}-new.pdf"
METADATA="tmp${1}-report.txt"
pdftk "${1}" dump_data output "$METADATA"
$EDITOR "$METADATA"
pdftk "${1}" update_info "$METADATA"  output "$OUTPUT"
touch -r "${1}" "${OUTPUT}"
}

Simply place the definition above into the .bashrc file in your home folder, then open a new terminal and it will be ready to use.

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    This is excellent, but I recommend quoting your variables when using them (e.g.: pdftk "${1}" dump_data ...) in case of PDF files with spaces or other special characters in their filename. – Niayesh Isky Mar 16 at 2:55
  • @NiayeshIsky Thanks! Done. Hopefully the filename does not have quotes in it? – CPBL Mar 17 at 3:03
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    Thanks! About quotes: Not in my case, at least :) (Sorry - I just noticed there is one $METADATA that is still unquoted, on the second pdftk line. I don't know if AU will allow such a small edit though.) – Niayesh Isky Mar 18 at 5:36
2

I have extensively tested the functionality of pdftk and exiftool. I have used exiftool both at command line and through a graphical window. These have been tested for small, medium size and very large PDF documents and found to have issues with the largest and most complex PDF documents. In my experience, the pdftk / exiftool have top functionality only for small and for simple-in-formatting PDF documents. For large and complex PDF documents (eg more than 80 pages with multiple fonts) images and/or characters may fall out from the last pages after the metadata has been edited. The solution may be in the use of Ghostview, which I saw just now. No doubt these programs will improve with time.

In the meantime, I have found a solution in using the present form of Wine in Ubuntu with a one-window tiny freeware program, which works also for these large, complex PDF documents: BeCyPDFMetaEdit (available eg from freeware libraries like SoftPedia).

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0

This is in the mouse library so you can edit PDF metadata from the command-line here as well.

$ npm install @mountbuild/mouse -g
$ mouse update input.pdf --title foo --author bar --subject baz -k one -k two

You can also set -p publisher, -c creator, -t0 created date, and -tn updated date.

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