Native Installers: pkg and dmg

macOS has its own installation formats that predate third-party package managers. Understanding .pkg installers and .dmg disk images helps you manage software that doesn’t come through Homebrew or MacPorts, including Xcode Command Line Tools and many commercial applications.

Package Types Overview

Format	Description	Management
`.pkg`	Installer package	pkgutil, installer
`.dmg`	Disk image containing `.app`	hdiutil, manual
`.app`	Application bundle	Manual drag to /Applications
`.mpkg`	Meta-package (multiple .pkg)	installer

.pkg Installers

What pkg Files Contain

A .pkg file is an archive containing:

Payload (files to install)
Scripts (pre/post install)
Bill of Materials (file manifest)
Package info

# Examine pkg contents
$ pkgutil --payload-files /path/to/package.pkg
$ pkgutil --bom /path/to/package.pkg

Installing pkg Files

# GUI installation
$ open package.pkg

# Command-line installation (requires sudo)
$ sudo installer -pkg package.pkg -target /
installer: Package name is My Package
installer: Installing at base path /
installer: The install was successful.

# Install to specific volume
$ sudo installer -pkg package.pkg -target /Volumes/OtherDisk

# Verbose installation
$ sudo installer -pkg package.pkg -target / -verbose

Managing Installed Packages

# List all installed packages
$ pkgutil --pkgs
com.apple.pkg.CLTools_Executables
com.apple.pkg.CLTools_SDK_macOS14
...

# Filter by pattern
$ pkgutil --pkgs | grep -i xcode

# Package information
$ pkgutil --pkg-info com.apple.pkg.CLTools_Executables
package-id: com.apple.pkg.CLTools_Executables
version: 15.0.0.0.1.1694021235
volume: /
location: /
install-time: 1694000000

# Files installed by a package
$ pkgutil --files com.apple.pkg.CLTools_Executables | head
Library/Developer/CommandLineTools/
Library/Developer/CommandLineTools/SDKs/
Library/Developer/CommandLineTools/SDKs/MacOSX.sdk
...

# Find which package owns a file
$ pkgutil --file-info /usr/bin/git
volume: /
path: /usr/bin/git
pkgid: com.apple.pkg.CLTools_Executables
...

Removing Packages

macOS doesn’t have a built-in package uninstaller. Removal requires:

# 1. Find installed files
$ pkgutil --files com.example.package > /tmp/files.txt

# 2. Review the file list
$ cat /tmp/files.txt

# 3. Remove files (carefully!)
$ cd /
$ sudo rm -rf $(pkgutil --files com.example.package)

# 4. Forget the package receipt
$ sudo pkgutil --forget com.example.package

Warning: Be very careful with rm -rf. Always review file lists first.

Xcode Command Line Tools

The most common .pkg on developer Macs:

# Check if installed
$ xcode-select -p
/Library/Developer/CommandLineTools

# Install
$ xcode-select --install
# Opens GUI prompt

# Or via softwareupdate
$ softwareupdate --list | grep "Command Line Tools"
$ softwareupdate -i "Command Line Tools for Xcode-15.0"

# Switch between Xcode and CLI tools
$ sudo xcode-select --switch /Applications/Xcode.app
$ sudo xcode-select --switch /Library/Developer/CommandLineTools

# Reset
$ sudo xcode-select --reset

Creating pkg Files

For distributing your own software:

# Create package from directory
$ pkgbuild --root /path/to/files \
           --identifier com.example.myapp \
           --version 1.0.0 \
           --install-location /Applications \
           myapp.pkg

# With scripts
$ pkgbuild --root /path/to/files \
           --identifier com.example.myapp \
           --version 1.0.0 \
           --scripts /path/to/scripts \
           --install-location /Applications \
           myapp.pkg

# Create distribution (combines multiple packages)
$ productbuild --distribution distribution.xml \
               --package-path /path/to/packages \
               final-installer.pkg

.dmg Disk Images

Working with DMG Files

# Mount disk image
$ hdiutil attach application.dmg
/dev/disk4          GUID_partition_scheme
/dev/disk4s1        Apple_APFS
/dev/disk5s1        Apple_APFS                   /Volumes/Application

# List mounted images
$ hdiutil info | grep image-path
image-path      : /path/to/application.dmg

# Unmount
$ hdiutil detach /Volumes/Application
# or
$ hdiutil detach /dev/disk5

Installing from DMG

Typical DMG workflow:

# Mount
$ hdiutil attach MyApp.dmg

# Copy app to Applications
$ cp -R /Volumes/MyApp/MyApp.app /Applications/

# Unmount
$ hdiutil detach /Volumes/MyApp

# Optional: delete dmg
$ rm MyApp.dmg

DMG Scripted Installation

#!/bin/bash
# install-from-dmg.sh

DMG_PATH="$1"
APP_NAME="$2"

# Mount
MOUNT_POINT=$(hdiutil attach "$DMG_PATH" -nobrowse | grep "/Volumes" | tail -1 | cut -f3)

# Copy
cp -R "$MOUNT_POINT"/*.app /Applications/ 2>/dev/null || \
cp -R "$MOUNT_POINT/$APP_NAME" /Applications/

# Unmount
hdiutil detach "$MOUNT_POINT"

echo "Installed to /Applications"

Creating DMG Files

# Create DMG from folder
$ hdiutil create -srcfolder /path/to/MyApp.app \
                 -volname "MyApp" \
                 -format UDZO \
                 MyApp.dmg

# Create empty DMG
$ hdiutil create -size 100m \
                 -fs HFS+ \
                 -volname "MyApp" \
                 MyApp.dmg

# Create read-write DMG (for customization)
$ hdiutil create -srcfolder /path/to/MyApp.app \
                 -volname "MyApp" \
                 -format UDRW \
                 MyApp-rw.dmg

# Convert to compressed read-only
$ hdiutil convert MyApp-rw.dmg -format UDZO -o MyApp.dmg

Internet-Enabled DMG

DMGs can auto-extract:

# Make DMG internet-enabled
$ hdiutil internet-enable -yes MyApp.dmg

When downloaded via Safari, the app is extracted and DMG deleted automatically.

Application Bundles (.app)

Bundle Structure

$ ls -la /Applications/Safari.app/Contents/
total 24
drwxr-xr-x   7 root  wheel   224 Dec 11 11:23 .
drwxr-xr-x   3 root  wheel    96 Dec 11 11:23 ..
drwxr-xr-x   3 root  wheel    96 Dec 11 11:23 _CodeSignature
-rw-r--r--   1 root  wheel  8572 Dec 11 11:23 Info.plist
drwxr-xr-x   3 root  wheel    96 Dec 11 11:23 MacOS
-rw-r--r--   1 root  wheel     8 Dec 11 11:23 PkgInfo
drwxr-xr-x  73 root  wheel  2336 Dec 11 11:23 Resources
drwxr-xr-x   5 root  wheel   160 Dec 11 11:23 XPCServices

# Key files
/Contents/Info.plist         # Application metadata
/Contents/MacOS/             # Executable
/Contents/Resources/         # App resources
/Contents/_CodeSignature/    # Code signature

App Metadata

# View Info.plist
$ plutil -p /Applications/Safari.app/Contents/Info.plist | head -20
{
  "BuildMachineOSBuild" => "23A344"
  "CFBundleDevelopmentRegion" => "English"
  "CFBundleExecutable" => "Safari"
  "CFBundleIdentifier" => "com.apple.Safari"
  "CFBundleInfoDictionaryVersion" => "6.0"
  "CFBundleName" => "Safari"
  "CFBundlePackageType" => "APPL"
  ...
}

# Get specific values
$ defaults read /Applications/Safari.app/Contents/Info.plist CFBundleVersion
17617.1.17.11.9

Installing Applications

# Copy to Applications
$ cp -R /path/to/MyApp.app /Applications/

# Or per-user
$ cp -R /path/to/MyApp.app ~/Applications/

# Remove quarantine (for trusted apps)
$ xattr -d com.apple.quarantine /Applications/MyApp.app

Uninstalling Applications

# Remove app bundle
$ rm -rf /Applications/MyApp.app

# Also remove:
# - ~/Library/Application Support/MyApp
# - ~/Library/Preferences/com.example.myapp.plist
# - ~/Library/Caches/com.example.myapp

# Find related files
$ mdfind "kMDItemCFBundleIdentifier == 'com.example.myapp'"
$ mdfind -name "myapp"

Software Update

Command-Line Software Updates

# List available updates
$ softwareupdate --list
Software Update found the following new or updated software:
* Label: macOS Sonoma 14.2.1-23C71
...

# Install all updates
$ sudo softwareupdate --install --all

# Install specific update
$ sudo softwareupdate --install "macOS Sonoma 14.2.1-23C71"

# Download only (don't install)
$ sudo softwareupdate --download --all

# Install and restart if needed
$ sudo softwareupdate --install --all --restart

Managing Update Behavior

# Check automatic update settings
$ defaults read /Library/Preferences/com.apple.SoftwareUpdate

# Enable automatic updates
$ sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticCheckEnabled -bool true
$ sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticDownload -bool true

# Disable automatic updates
$ sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticCheckEnabled -bool false

App Store from Command Line

mas (Mac App Store CLI)

# Install mas
$ brew install mas

# Sign in (may require App Store sign-in first)
$ mas signin email@example.com

# Search
$ mas search Xcode
497799835  Xcode (15.0)

# Install by ID
$ mas install 497799835

# List installed
$ mas list

# Outdated apps
$ mas outdated

# Upgrade all
$ mas upgrade

Summary

Native macOS installation methods:

Method	Use Case	Management
`.pkg`	System tools, CLT	pkgutil, installer
`.dmg`	App distribution	hdiutil
`.app`	Direct app bundle	cp, rm
App Store	Sandboxed apps	mas
softwareupdate	macOS/system	softwareupdate

Key commands:

Task	Command
Install pkg	`sudo installer -pkg file.pkg -target /`
List packages	`pkgutil --pkgs`
Package files	`pkgutil --files com.example.pkg`
Forget package	`sudo pkgutil --forget com.example.pkg`
Mount dmg	`hdiutil attach file.dmg`
Unmount dmg	`hdiutil detach /Volumes/Name`
System updates	`softwareupdate --list`
Install CLT	`xcode-select --install`

Native installers complement package managers for software that requires system-level installation or comes directly from vendors.

Keyboard shortcuts

macOS and Unix: The Complete Guide