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PDF Tools README

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The pdf-tools Wiki is maintained at https://pdftools.wiki. Head to the site if you find it easier to navigate a website for reading a manual. All the topics on the site are listed at https://pdftools.wiki/impulse.

Table of Contents

About PDF Tools

PDF Tools is, among other things, a replacement of DocView for PDF files. The key difference is that pages are not pre-rendered by, say, ghostscript and stored in the file-system, but rather created on-demand and stored in memory.

This rendering is performed by a special library named, for whatever reason, poppler, running inside a server program. This program is called epdfinfo and its job is to successively read requests from Emacs and produce the proper results, i.e. the PNG image of a PDF page.

Actually, displaying PDF files is just one part of pdf-tools. Since poppler can provide us with all kinds of information about a document and is also able to modify it, there is a lot more we can do with it. Watch this video for a detailed demo!

Installing pdf-tools

Installing this package via NonGNU ELPA or MELPA or any of the other package managers is straightforward and should just work! You should not require any manual changes. The documentation below is only if you are installing from source, or for troubleshooting / debugging purposes.

pdf-tools requires a server epdfinfo to run against, which it will try to compile and build when it is activated for the first time. The following steps need to be followed in this order, to install pdf-tools and epdfinfo correctly:

  • Installing the epdfinfo server
  • Installing pdf-tools elisp code

Installing the epdfinfo server

If you install pdf-tools via NonGNU ELPA or MELPA, you don’t need to worry about this separate server installation at all.

Note: You’ll need GNU Emacs ≥ 26.3 and some form of a GNU/Linux OS. Other operating systems are not officially supported, but pdf-tools is known to work on many of them.

The epdfinfo install script takes care of installing all the necessary pre-requisites on supported operating systems (see list below). See the section on I want to add support for pdf-tools on My Fav OS. How do I do that? to learn how to add your favorite Operating System to this list.

Similarly, package-managers are not officially supported, but pdf-tools is known to be available on some of them. See the section on Installing the epdfinfo server from package managers to avoid manual installation of server / server prerequisites.

Installation Instructions for epdfinfo:

$ git clone https://github.com/vedang/pdf-tools
$ cd /path/to/pdf-tools
$ make -s # If you don't have make installed, run ./server/autobuild and it will install make

This should give you no error and should compile the epdfinfo server. If you face a problem, please report on the issue tracker!

The following Operating Systems / package managers are supported. Note: The package manager used to install pre-requisites should be installed on your OS for the script to work:

  • Debian-based systems (debian, ubuntu): apt-get
  • Fedora: dnf
  • macOS: brew
  • Windows (MSYS2/ MingW): pacman
  • NixOS: nix-shell
  • openSUSE (Tumbleweed and Leap): zypper
  • Void Linux: xbps-install
  • Apline Linux: apk
  • FreeBSD: pkg
  • OpenBSD: pkg_add
  • NetBSD: pkgin
  • Arch Linux: pacman
  • Gentoo: emerge
  • CentOS: yum

Installing the epdfinfo server from package managers

pdf-tools can be directly installed from the package manager on some operating systems. Note that the packages available on these package managers are not maintained by the author and might be outdated.

Installing the epdfinfo server from source on Windows (+ Gotchas)

If using the GNU binaries for Windows, support for PNG and zlib must first be installed by copying the appropriate dlls into emacs’ bin/ directory. Most third-party binaries come with this already done.
  1. install MSYS2 and update the package database and core packages using the instructions provided.
  2. Open mingw64 shell (Note: You must use mingw64.exe and not msys2.exe)
  3. Compile the epdfinfo server using Installation steps described in Installing the epdfinfo server
  4. This should produce a file server/epdfinfo.exe. Copy this file into the pdf-tools/ installation directory in your Emacs.
  5. Make sure Emacs can find epdfinfo.exe. Either add the MINGW install location (e.g. C:/msys2/mingw64/bin) to the system path with setx PATH "C:\msys2\mingw64\bin;%PATH%" or set Emacs’s path with (setenv "PATH" (concat "C:\\msys64\\mingw64\\bin;" (getenv "PATH"))). Note that libraries from other GNU utilities, such as Git for Windows, may interfere with those needed by pdf-tools. pdf-info-check-epdinfo will succeed, but errors occur when trying to view a PDF file. This can be fixed by ensuring that the MSYS libraries are always preferred.
  6. pdf-tools will successfully compile using Cygwin, but it will not be able to open PDFs properly due to the way binaries compiled with Cygwin handle file paths. Please use MSYS2.

Installing the epdfinfo server from source on macOS (+ Gotchas)

On macOS, autobuild adjusts PKG_CONFIG_PATH so that pdf-tools can find some of the keg-only packages installed by brew. It is recommended that you review the output logs printed by brew during the installation process to also export the relevant paths to the appropriate ENV variables.

Common installation gotchas

In case you decide to install libpoppler from source, make sure to run its configure script with the --enable-xpdf-headers option.

Installing optional features

One feature – following links of a PDF document by plain keystrokes – requires imagemagick’s convert utility. This requirement is optional, the installation process will detect if you have imagemagick installed or not.

Installing pdf-tools elisp code

pdf-tools requires tablist package (>= version 0.70) to be installed, for it to work correctly. Please make sure that the latest version of tablist is installed.

We have already run the steps necessary to install pdf-tools as part of the server installation! These are:

$ git clone https://github.com/vedang/pdf-tools
$ cd /path/to/pdf-tools
$ make -s

If the make command produced the ELP file pdf-tools-${VERSION}.tar you are fine! This package contains all the necessary files for Emacs and may be installed by either using

$ make install-package

or executing the Emacs command

M-x package-install-file RET pdf-tools-${VERSION}.tar RET

You can test if the package has been installed correctly, by running

M-x pdf-info-check-epdfinfo RET

To complete the installation process, you need to activate the package by putting the code below somewhere in your .emacs. Alternatively, and if you care about startup time, you may want to use the loader version instead.

(pdf-tools-install)  ; Standard activation command
(pdf-loader-install) ; On demand loading, leads to faster startup time

Once the Installation process is complete, check out Easy Help for PDF Tools features and Configuring PDF Tools features to get started!

Updating pdf-tools

Some day you might want to update this package via git pull and then reinstall it. Sometimes this may fail, especially if Lisp-Macros are involved and the version hasn’t changed. To avoid this kind of problems, you should delete the old package via list-packages, restart Emacs, run make distclean and then reinstall the package. Follow the steps described in Installing pdf-tools elisp code.

This also applies when updating via MELPA / NonGNU ELPA (except for running the make distclean step).

Features

View
View PDF documents in a buffer with DocView-like bindings. More information here.
Isearch
Interactively search PDF documents like any other buffer, either for a string or a PCRE.
Occur
List lines matching a string or regexp in one or more PDF documents.
Follow
Click on highlighted links, moving to some part of a different page, some external file, a website or any other URI. Links may also be followed by keyboard commands.
Annotations
Display and list text and markup annotations (like underline), edit their contents and attributes (e.g. color), move them around, delete them or create new ones and then save the modifications back to the PDF file. More information here.
Attachments
Save files attached to the PDF-file or list them in a dired buffer.
Outline
Use imenu or a special buffer (M-x pdf-outline) to examine and navigate the PDF’s outline.
SyncTeX
Jump from a position on a page directly to the TeX source and vice versa.
Virtual
Use a collection of documents as if it were one, big single PDF.
Misc
  • Display PDF’s metadata.
  • Mark a region and kill the text from the PDF.
  • Keep track of visited pages via a history.
  • Apply a color filter for reading in low light conditions.

View and Navigate PDFs

PDFView Mode is an Emacs PDF viewer. It displays PDF files as PNG images in Emacs buffers. PDFs are navigable using DocView-like bindings. Once you have installed pdf-tools, opening a PDF in Emacs will automatically trigger this mode.

Keybindings for navigating PDF documents

Navigation
Scroll Up / Down by Page-fullspace / backspace
Scroll Up / Down by LineC-n / C-p
Scroll Right / LeftC-f / C-b
First Page / Last Page<, M-< / >, M->
Next Page / Previous Pagen / p
Incremental Search Forward / BackwardC-s / C-r
Occur (list all lines containing a phrase)M-s o
Jump to Occur LineRETURN
Pick a Link and JumpF
Incremental Search in Linksf
History Back / Forwardsl / r
Display Outlineo
Jump to Section from OutlineRETURN
Jump to PageM-g g
Store position / Jump to position in registerm / '

Note that pdf-tools renders the PDF as images inside Emacs. This means that all the keybindings of image-mode work on individual PDF pages as well.

Image Mode
image-scroll-rightC-x > / <remap> <scroll-right>
image-scroll-leftC-x < / <remap> <scroll-left>
image-scroll-upC-v / <remap> <scroll-up>
image-scroll-downM-v / <remap> <scroll-down>
image-forward-hscrollC-f / right / <remap> <forward-char>
image-backward-hscrollC-b / left / <remap> <backward-char>
image-bob<remap> <beginning-of-buffer>
image-eob<remap> <end-of-buffer>
image-bol<remap> <move-beginning-of-line>
image-eol<remap> <move-end-of-line>
image-scroll-down<remap> <scroll-down>
image-scroll-up<remap> <scroll-up>
image-scroll-left<remap> <scroll-left>
image-scroll-right<remap> <scroll-right>

Keybindings for manipulating display of PDF

Display
Zoom in / Zoom out+ / -
Fit Height / Fit Width / Fit PageH / W / P
Trim Margins (set slice to bounding box)s b
Reset Marginss r
Reset Zoom0
Rotate PageR

Annotations

pdf-tools supports working with PDF Annotations. You can display and list text and markup annotations (like squiggly, highlight), edit their contents and attributes (e.g. color), move them around, delete them or create new ones and then save the modifications back to the PDF file.

Keybindings for working with Annotations

Annotations
List AnnotationsC-c C-a l
Jump to Annotations from ListSPACE
Mark Annotation for Deletiond
Delete Marked Annotationsx
Unmark Annotationsu
Close Annotation Listq
Enable/Disable Following AnnotationsC-c C-f
Add and Edit AnnotationsSelect region via Mouse selection.
Then left-click context menu OR keybindings below
Add a Markup AnnotationC-c C-a m
Add a Highlight Markup AnnotationC-c C-a h
Add a Strikeout Markup AnnotationC-c C-a o
Add a Squiggly Markup AnnotationC-c C-a s
Add an Underline Markup AnnotationC-c C-a u
Add a Text AnnotationC-c C-a t
Highlight an arbitrary regionSection region with Mouse Drag (Hold down Meta and
drag). Then C-c C-a h to highlight that region.

Working with AUCTeX

Keybindings for working with AUCTeX

Syncing with AUCTeX
Refresh File (e.g., after recompiling source)g
Jump to PDF Location from SourceC-c C-g
Jump Source Location from PDFC-mouse-1

Miscellaneous features

Keybindings for miscellaneous features in PDF tools

Miscellaneous
Print FileC-c C-p

Easy Help for PDF Tools features

M-x pdf-tools-help RET

Run M-x pdf-tools-help inside Emacs, as shown above. It will list all the features provided by pdf-tools as well as the key-bindings for these features.

Configuring PDF Tools features

Once you have read through the features provided by pdf-tools, you probably want to customize the behavior of the features as per your requirements. Full customization of features is available by running the following:
M-x pdf-tools-customize RET

Known problems

linum-mode

pdf-tools does not work well together with linum-mode and activating it in a pdf-view-mode, e.g. via global-linum-mode, might make Emacs choke.

display-line-numbers-mode

This mode is an alternative to linum-mode and is available since Emacs 26. pdf-tools does not work well with it. For example, it makes horizontal navigation (such as C-f, C-b, C-x < or C-x > ) in a document impossible.

auto-revert

Autorevert works by polling the file-system every auto-revert-interval seconds, optionally combined with some event-based reverting via file notification. But this currently does not work reliably, such that Emacs may revert the PDF-buffer while the corresponding file is still being written to (e.g. by LaTeX), leading to a potential error.

With a recent AUCTeX installation, you might want to put the following somewhere in your dotemacs, which will revert the PDF-buffer after the TeX compilation has finished.

(add-hook 'TeX-after-compilation-finished-functions #'TeX-revert-document-buffer)

sublimity

L/R scrolling breaks while zoomed into a pdf, with usage of sublimity smooth scrolling features

Text selection is not transparent in PDFs OCRed with Tesseract

In such PDFs the selected text becomes hidden behind the selection; see this issue, which also describes the workaround in detail. The following function, which depends on the qpdf.el package, can be used to convert such a PDF file into one where text selection is transparent:

(defun my-fix-pdf-selection ()
  "Replace pdf with one where selection shows transparently."
  (interactive)
  (unless (equal (file-name-extension (buffer-file-name)) "pdf")
    (error "Buffer should visit a pdf file."))
  (unless (equal major-mode 'pdf-view-mode)
    (pdf-view-mode))
  ;; save file in QDF-mode
  (qpdf-run (list
             (concat "--infile="
                     (buffer-file-name))
             "--qdf --object-streams=disable"
             "--replace-input"))
  ;; do replacements
  (text-mode)
  (read-only-mode -1)
  (while (re-search-forward "3 Tr" nil t)
    (replace-match "7 Tr" nil nil))
  (save-buffer)
  (pdf-view-mode))

Note that this overwrites the PDF file visited in the buffer from which it is run! To avoid this replace the --replace-input with (concat "--outfile=" (file-truename (read-file-name "Outfile: "))).

Key-bindings in PDF Tools

  • Keybindings for navigating PDF documents
  • Keybindings for working with Annotations
  • Keybindings for manipulating display of PDF
  • Keybindings for working with AUCTeX
  • Keybindings for miscellaneous features in PDF tools

Tips and Tricks for Developers

Turn on debug mode

M-x pdf-tools-toggle-debug RET

Toggling debug mode prints information about various operations in the *Messages* buffer, and this is useful to see what is happening behind the scenes

Run Emacs lisp tests locally

You can go to the pdf-tools folder and run make test to run the ERT tests and check if the changes you have made to the code break any of the tests.

The tests are written in ERT, which is the built-in testing system in Emacs. However, they are run using Cask which you will have to install first, if you don’t have it already. You can install Cask by following the instructions on their site at https://github.com/cask/cask

Run server compilation tests locally

You can go to the pdf-tools folder and run make server-test to check if the changes you have made to the server code break compilation on any of the supported operating systems.

The tests build Podman images for all supported operating systems, so you will have to install Podman first, if you don’t have already. You can install Podman by following the instructions on their site at https://podman.io/getting-started/installation

Podman is compatible with Docker, so if you already have docker installed, you should be able to alias podman=docker on your shell and run the tests, without having to install Docker. (Note: I have not tested this)

Add a Dockerfile to automate server compilation testing

The server/test/docker folder contains Dockerfile templates used for testing that the epdfinfo server compiles correctly on various operating systems (more details here).

To see the list of operating systems where compilation testing is supported, run make server-test-supported. To see the list of operating systems where testing is unsupported, run make server-test-unsupported. To add support, look into the server/test/docker/templates folder (ubuntu files are a good example to refer to)

Issue Template for Bug Reports

Please use the ‘Bug Report’ issue template when reporting bugs. The template is as follows:

Describe the bug

A clear and concise description of what the bug is.

Steps To Reproduce the behaviour:

  1. Go to ‘…’
  2. Click on ‘....’
  3. Scroll down to ‘....’
  4. See error

What is the expected behaviour?

A clear and concise description of what you expected to happen.

Desktop

Please complete the following information:

  • OS: [eg: MacOS Catalina]
  • Emacs Version: [This should be the output of M-x emacs-version ]
  • Poppler Version: [eg: output of brew info poppler and similarly for other OSs]

Your pdf-tools install

Please complete the following information:

  • pdf-tools Version: [ M-x package-list-packages -> Search for pdf-tools -> Hit Enter and copy all the details that pop up in the Help buffer]
  • pdf-tools customization / configuration that you use:

Additional context

  • If you are reporting a crash, please try and add the Backtrace / Stacktrace of the crash.
  • If you are reporting a bug, please try and attach an example PDF file where I can reproduce the bug.
  • If you can attach screenshots or recordings, that is a great help
  • Please try reproducing the bug yourself on Vanilla Emacs before reporting the problem.

FAQs

Epdfinfo has stopped working!

Have you upgraded poppler recently? This can cause epdfinfo to stop working, since it was compiled with the previous version of poppler. Just run M-x pdf-tools-install and this should be fixed.

PDFs are not rendering well!

pdf-tools version 1.1.0 release changed the default value of pdf-view-use-scaling to t (previously, it was nil). This has been done keeping in mind that most modern monitors are HiDPI screens, so the default configuration should cater to this user. If you are not using a HiDPI screen, you might have to change this value to nil in your configuration
(setq pdf-view-use-scaling nil)

to scale the images correctly when rendering them.

What Emacs versions does pdf-tools support?

pdf-tools supports the 3 latest versions of Emacs major releases. At the moment of this writing, this means that the minimum supported Emacs version is 26.3.

I want to add support for pdf-tools on “My Fav OS”. How do I do that?

I’m working on automating pdf-tools installation as much as possible, in order to improve the installation experience. If you want to add support for a new / currently unsupported Operating System, please modify the server/autobuild script. Say you want to support a new Operating System called MyFavOS. You need to do the following work:
  1. Search for the Figure out where we are section. Here, add a call to os_myfavos right below handle_options at the end of the existing call chain. Here we try and pick up the correct Operating System and install the relevant dependencies.
  2. Add handling for the --os argument in os_argument for myfavos, so that the appropriate function can be called to install pre-requisites. --os is the argument that we pass to the script from the command-line to indicate which OS we are on.
  3. Create a os_myfavos function. This function checks if we are running on MyFavOS. If we are running on MyFavOS, it sets up PKGCMD, PKGARGS and PACKAGES variables so that the appropriate package manager can install the dependencies as part of the rest of the autobuild script.
  4. If you are adding support for your favorite operating system, consider adding automated testing support as well, to help me ensure that epdfinfo continues to compile correctly. See Add a Dockerfile to automate server compilation testing for more details.

The idea here is to make the server/autobuild file the single place from which installation can happen on any Operating System. This makes building pdf-tools dead simple via the Makefile.

This seems like a lot of work, but it is not. If you need a reference, search for os_gentoo or os_debian in the server/autobuild file and see how these are setup and used. The functions are used to install dependencies on Gentoo and Debian respectively, and are simple to copy / change.

When you make your changes, please be sure to test the elisp changes as well as the server code changes as described in the linked articles.

I am on a Macbook M1 and pdf-tools installation fails with a stack-trace

There have been a number of issues around pdf-tools installation problems on M1. M-x pdf-tools-install throws the following stack trace:
1 warning generated.
ld: warning: ignoring file /opt/homebrew/opt/gettext/lib/libintl.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
ld: warning: ignoring file /opt/homebrew/Cellar/glib/2.72.1/lib/libglib-2.0.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
ld: warning: ignoring file /opt/homebrew/Cellar/poppler/22.02.0/lib/libpoppler-glib.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
ld: warning: ignoring file /opt/homebrew/Cellar/glib/2.72.1/lib/libgobject-2.0.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
ld: warning: ignoring file /opt/homebrew/Cellar/poppler/22.02.0/lib/libpoppler.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
ld: warning: ignoring file /opt/homebrew/Cellar/cairo/1.16.0_5/lib/libcairo.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
ld: warning: ignoring file /opt/homebrew/Cellar/libpng/1.6.37/lib/libpng16.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
ld: warning: ignoring file /opt/homebrew/Cellar/zlib/1.2.11/lib/libz.dylib, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
Undefined symbols for architecture x86_64:

This happens because M1 architecture is ARM64, whereas the Emacs App you are using has been compiled for the x86_64 architecture. The way to solve this problem is to install a version of Emacs which has been compiled for the M1. As of today, [2022-05-09 Mon], the latest version of Emacs available on https://emacsformacosx.com/ is natively compiled and you will not face these issues on it. Please remove your current Emacs App and install it from https://emacsformacosx.com/.

Thank you.

PS: How do I know if the Emacs I’m running has been compiled correctly?

You can see this by opening the Activity Monitor, selecting Emacs, clicking on the Info key, and then clicking on Sample. The Code Type field in the Sample output will show you how your Application has been compiled. Here is the output for EmacsForMacOSX (you can see that it’s ARM64):

Sampling process 61824 for 3 seconds with 1 millisecond of run time between samples
Sampling completed, processing symbols...
Analysis of sampling Emacs-arm64-11 (pid 61824) every 1 millisecond
Process:         Emacs-arm64-11 [61824]
Path:            /Applications/Emacs.app/Contents/MacOS/Emacs-arm64-11
Load Address:    0x1007f0000
Identifier:      org.gnu.Emacs
Version:         Version 28.1 (9.0)
Code Type:       ARM64
Platform:        macOS

If your Emacs is compiled for x86, the Code Type will be x86_64.

I am a developer, making changes to the pdf-tools source code

Thank you for taking the time to contribute back to the code. You may find some useful notes in the Tips and Tricks for Developers section. Please be sure to check it out!