Convert ACSM files to PDF/EPUBs with one command on Linux.
This software does not utilize Adobe Digital Editions nor Wine. It is completely free and open-source software written natively for Linux.
Knock was taken down between late 2022 and mid-2024 pending a legal concern that has now been resolved.
- Run
uname -ms
and, based on the output, download the latest corresponding release. cd
into the directory that knock is in (e.g.cd ~/Downloads
).- Run
mv knock-version-arch-os knock
to rename the binary toknock
. - Run
chmod +x knock
to make it executable. - Run
./knock ./path/to/book.acsm
to perform the conversion. - Run
mv knock ~/.local/bin
to allow it to be run from anywhere (might not work on some distributions).
Nix and NixOS (with flakes enabled)
If you are on a system with Nix, you can use the following.
nix profile install github:BentonEdmondson/knock
If you are on NixOS, you can add the flake to your system config.
There are no userspace runtime dependencies.
Knock should work on any ACSM file, but it has been specifically verified to work on ACSM files purchased from eBooks.com, Kobo, and Google Play.
Before buying your ebook, check if it is available for free on Project Gutenberg.
Install Nix if you don't have it. Enable flakes if you haven't.
nix build
nix flake update
nix run .#tests -- ./tests/workspace
Test books can be found here.
nix run .#formatter
The name comes from the D&D 5e spell for freeing locked items:
2nd level transmutation
Casting Time: 1 action
Range: 60 feet
Components: V
Duration: Instantaneous
Classes: Bard, Sorcerer, Wizard
Choose an object that you can see within range. The object can be a door, a box, a chest, a set of manacles, a padlock, or another object that contains a mundane or magical means that prevents access. A target that is held shut by a mundane lock or that is stuck or barred becomes unlocked, unstuck, or unbarred. If the object has multiple locks, only one of them is unlocked. If you choose a target that is held shut with arcane lock, that spell is suppressed for 10 minutes, during which time the target can be opened and shut normally. When you cast the spell, a loud knock, audible from as far away as 300 feet, emanates from the target object.
This software is licensed under GPLv3. The linked libraries have various licenses.