CODEWITHSUNDEEP
macosextractdmg
Henry Manister
Henry Manister

Reputation: 216

Extract from DMG

How to extract content of DMG without mounting it? I want add autoupdate system to my application. It downloads DMG from website, then extract new version of application from it.

Upvotes: 17

Views: 51857

Answers (5)

Shivendra Agarwal
Shivendra Agarwal

Reputation: 688

import subprocess
import re
import shutil

def extract_dmg(download_path, extract_path):
    # Mount the DMG file and capture the output
    output = subprocess.check_output(['hdiutil', 'attach', '-nobrowse', '-readonly', download_path]).decode('utf-8')

    # Extract the mounted volume name from the output
    mounted_volume_name = re.search(r'/Volumes/([^ ]*)', output).group(1)

    # Use the mounted volume name to copy files
    shutil.copytree(f'/Volumes/{mounted_volume_name}/', extract_path)

    # Detach the volume
    subprocess.run(['hdiutil', 'detach', f'/Volumes/{mounted_volume_name}'])

# Usage
download_path = "/path/to/your/download.dmg"
extract_path = "/path/to/extract"

extract_dmg(download_path, extract_path)

Upvotes: 1

Dre Adesina
Dre Adesina

Reputation: 21

The best and easy way to extract a .dmg is to use the hdituil and the pkgutil. The .dmg contents has a .pkg files in it. Two options is to go from .dmg directly and extract the files or first mount the .dmg and then extract the .pkg. Here is a link to glorious post that saves me from installing MacOS installer when all hope was lost. Credit to this amazing post won't stole that also it's a result of good searching query lol https://medium.com/macoclock/extracting-applications-and-other-files-from-pkg-files-on-macos-f885376f1ef3

Upvotes: 0

Alston
Alston

Reputation: 2137

Dmg is just a format used for MacOS. It's a not compressed file format like zip or tar.gz You have several choices to mount it. Here are some options.

  1. Double click on it to mount it.
  2. Use hdiutil attach your.dmg to mount the dmg file. After mounting on it, operating your command line to extract the files you want out.

Upvotes: 4

Mengdi Gao
Mengdi Gao

Reputation: 850

Some .dmg files can be extracted by using 7-zip.

$ 7z x your.dmg
$ ls
your.dmg
0.MBR
1.Primary GPT Header
2.Primary GPT Table
3.free
4.hfs
5.free
6.Backup GPT Table
7.Backup GPT Header

...and after extracted the 4.hfs file:

$ 7z x 4.hfs

...you'll get the content of the .dmg file.

You could also mount the .dmg in Mac OS X using hdiutil command (which is also used by Homebrew Cask).

Please refer to this Ask Ubuntu question for more use cases on Linux.

Upvotes: 17

Brighid McDonnell
Brighid McDonnell

Reputation: 4343

Doing that is working counter to the design of DMGs, so it's very painful. DMGs are designed to be mounted, that is their whole raison d'être. You would need to rely on experimental code if you wanted to do something like that. You are probably better served by using a non-DMG archive such as a zip file, or by making your automatic updating process download, mount, and unmount the DMG file you provide.

Upvotes: -5

Related Questions