Mac OS

The best OS a parent's money can buy

• Steve Jobs, probably

Keyboard Shortcuts

What you'll see below is incomplete, for up to date information, check Apple's documentation on keyboard shortcuts. Dan Rodney's compilation is a great source as well.

Finder

Navigation

Sleep, Restart, Shut Down, Log Out

Document Editing

These work when editing text using Safari, Notes, and Mail, and any Mac OS application in general. They aren't arbitrary, they're the emacs hotkeys, and work on many applications, not just ones on Mac OS.

Cursor Movement

If you're ever stuck without arrow keys (it could happen!) you can take advantage of these 4 shortcuts.

Navigating Folders

Opening Folders

Adjusting the Finder Window

Safari

Mail

Screenshot directly from terminal

There's a hidden terminal command screencapture that you can use to capture a screenshot of your current window.

• Capture the screen, save to example.png

  screencapture 'example.png'
  

• Capture the screen, save to the clipboard

  screencapture -c
  

• Capture the screen, disable the "click" sound effect

  screencapture -x 'example.png'
  

• Capture the screen, (but after 10 second delay)

  screencapture -T 10 'example.png' &
  

Start screen recording from the terminal

You can even use screencapture to record video. The -V flag specifies to capture a video and the -A flag specifies to capture audio as well.

• Record the screen for 10 seconds

  screencapture -V 10 'example.mp4' &
  

Change default screenshot location

I like to put my screenshots in the ~/Downloads directory. Luckily there's a terminal command for that.

• Set the directory of all future screenshots.

  defaults write com.apple.screencapture location ~/Downloads && killall SystemUIServer
  

Change default screenshot filetype

By default, screenshots save as PNG files, but you can change this

• Change default screenshot filetype from PNG to JPG

  defaults write com.apple.screencapture type -string 'jpg' && killall SystemUIServer
  

• Change the screen capture filename to screenshot

  defaults write com.apple.screencapture name -string 'screenshot' && killall SystemUIServer
  

Audio

Custom Sound Effects

The default system alert sounds are located in /System/Library/Sounds, and you can place your own custom alert sounds in the ~/Library/Sounds directory. Your custom alert sound must be an AIFF file (e.g. example.aiff).

• Use ffmpeg to convert an .mp3 to .aiff

  ffmpeg -i './input.mp3' "${HOME}/Library/Sounds/custom.aiff"
  

If you'd like to discover sounds on your computer, use a recursive glob to discover audio files within the system library

print -l /System/Library/**/*.aiff

For instance, to play a sound, use the afplay command, and provide it the sound file you'd like to play. For example, the command below plays the default alert sound on macOS

afplay '/System/Library/Sounds/Tink.aiff'

Move cursor with the mouse in terminal

This is a cool trick I just discovered. Start typing out a command on the terminal, and then hold ⌥

Now try clicking on a different part of the command you're entering. It will move the cursor to that location!

Update Software in the Terminal

You can actually update the software on your computer directly from the terminal.

• List available software updates

  softwareupdate -l
  

• The -l flag is the list option

• Install all updates

  # Short form
  sudo softwareupdate -iaR
  
  # Long form
  sudo softwareupdate --install --all --restart
  

  • The -i flag is the install option
  • The -a flag is the all option
  • The -r flag is the restart option, so the computer will restart and install the updates after they are downloaded

Fonts

• The default terminal font, SF Mono, is by default hidden from the Font Book, and is available exclusively for use in the terminal app. To copy SF Mono to your computer's Font Book, run this command.

  cp -R /System/Applications/Utilities/Terminal.app/Contents/Resources/Fonts/* /Library/Fonts
  

Disable User Photo

• Although the GUI doesn't give us an option to disable user-pictures, you can do it with the terminal commands below.

  # Delete the image chosen during OS installation
  sudo dscl . delete /Users/${USER} Picture
  
  # Delete an image chosen by the user later on
  sudo dscl . delete /Users/${USER} JPEGPhoto
  

Setting Keyboard Shortcuts from Terminal

Store your keyboard shortcuts in the directory ~/Library/KeyBindings/DefaultKeyBinding.dict. Note that you have to first create ~/Library/KeyBindings since it won't exist at first.

• @ : ⌘

• ^ : ⌃

• ~ : ⌥

• $ : ⇧

• ← : \U2190

• ↑ : \U2191

• → : \U2192

• ↓ : \U2193

Fix Permissions

If you mess up your /etc files, like I did when I accidentally made every file executable, you can run this command to reset all of the permissions.

• Reset system file permissions to default

  diskutil resetUserPermissions / $(id -u)
  

If you mess up your /etc/sudoers file, you'll have to boot into single-user mode with ⌘ S during power on. From there, you can enter the following commands.

• Reset sudoers file

  mount -uw /
  chown root:wheel /etc/sudoers
  chmod 440 /etc/sudoers
  reboot
  reboot
  

Customize Launch Application for File Extension

The property list file that controls which app launches for a particular filetype is located deep in Launch Services.

• Open the Launch Services properties list file

  open file:///Users/${USER}/Library/Preferences/com.apple.LaunchServices/com.apple.launchservices.secure.plist
  

Default Application

You can install the command duti on homebrew to configure the default application that opens when you click on a file with a particular file extension. I've included an example below:

• Setting default application used for .c files.

  # Set apple as the default editor for .c files
  duti -s com.apple.Xcode public.c editor
  # Check the current handlers performed by a UTI
  duti -l com.apple.Safari
  # Describe information about the default app for extension `mp4`
  duti -x mp4
  duti -x mp4
  

Convert SVG to PNG

Install librsvg, which is built by GNOME

If you want to convert example.svg into a 1024x1024 PNG file, you have a few choices. These are ordered from best to worst.

• Using librsvg:

  # If necessary
  brew install librsvg
  
  rsvg-convert -w 4096 -h 4096 example.svg -o example.png
  

• Using magick resize

  # If necessary
  brew install imagemagick
  
  magick convert \
      -resize '1024x1024' \
      -background 'none' \
      'input.svg' 'output.png'
  

• Using qlmanage, the built-in command-line utility for QuickLook:

  qlmanage -ts 1024 -o . example.svg
  

avconvert

I'm going to write some notes about conversions between audio and video file formats here. Some useful commands will appear below, but first I want to give a breakdown of the ecosystem around audio, video, and image file formats.

First, the Moving Picture Experts Group (MPEG) is a group formed by ISO and IEC to standardize the way audio and visual data is compressed and transmitted across the internet. MPEG-4 is a method of defining compression of audio and visual (AV) digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG). It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG)

• Encode MOV file video.mov as an H.265 (HEVC) encoded M4V file video.m4v preserving the original video resolution

  avconvert -p 'PresetHEVCHighestQuality' -s 'video.mov' -o 'video.mp4'
  

• Encode MOV file video.mov as an H.265 (HEVC) encoded M4V file with 1080p resolution

  # You can add the '-q' flag to suppress output
  avconvert -p 'PresetHEVC1920x1080' -s 'video.mov' -o 'video@1080p.m4v'
  

• Encode MOV file video.mov as an H.264 encoded MOV file with 720p resolution

  avconvert -p 'Preset640x480' -s 'video.mov' -o 'video@720p.mov'
  

• Encode MOV file video.mov as an H.264 encoded MOV file with 420p resolution

    ```shell
    avconvert -p 'Preset640x480' -s 'video.mov' -o 'video@420p.mov'
    ```
  

Convert MP3 to M4A

• Convert song.mp3 into an AAC encoded M4A audio file song.m4a

  # -v is for "verbose"
  avconvert -v -p PresetAppleM4A -s ~/Desktop/song.mp3 -o ~/Desktop/song.m4a
  

networksetup

The networksetup command allows you to configure your System Preference's Network settings directly from your terminal.

• Get the current DNS servers

  networksetup -getdnsservers Wi-Fi
  

• Configure the DNS servers

  networksetup -setdnsservers Wi-Fi 1.1.1.1 1.0.0.1 2606:4700:4700::1111 2606:4700:4700::1001
  

• Get the local machine's MAC address

  networksetup -getmacaddress Wi-Fi | awk '{print $3}'
  

• Configure the SOCKS proxy

  ssh -fNCD 3339 bastion@remote.site
  networksetup -setsocksfirewallproxy Wi-Fi 127.0.0.1 3339
  networksetup -setsocksfirewallproxy Wi-Fi 127.0.0.1 3339
  

• Enable the SOCKS proxy

  networksetup -setsocksfirewallproxystate Wi-Fi on
  

• Disable the SOCKS proxy

  networksetup -setsocksfirewallproxystate Wi-Fi off
  

• List preferred wireless networks

  networksetup -listpreferredwirelessnetworks en0
  

• Remove a preferred wireless network

  networksetup -removepreferredwirelessnetwork en0 <network>
  

• Connect to a WiFi Network

  networksetup -setairportnetwork en0 <WiFi name> <password>
  

• List order of network devices used to connect to the internet

  networksetup -listnetworkserviceorder
  

• Check if Wi-Fi is currently enabled

  networksetup -getnetworkserviceenabled Wi-Fi
  

• Get the name of the current network an interface is connected to

  networksetup -getairportnetwork en0
  

• Print detailed information about the current network connection

  networksetup -getinfo Wi-Fi
  

  # dhcp configuration
  # IP address: 10.26.206.163
  # Subnet mask: 255.255.0.0
  # Router: 10.26.0.1
  # Client ID:
  # IPv6: Automatic
  # IPv6 IP address: none
  # IPv6 Router: none
  # Wi-Fi ID: 6c:96:cf:dc:e5:cb
  # Wi-Fi ID: 6c:96:cf:dc:e5:cb
  

airport

There is a hidden command, called airport.

• Adding the airport command to the ${PATH}

  file=/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport
  >> ~/.zshrc < =(<<<"path+=(${file})")
  

• Scan available WiFi networks

  airport -s
  

• Disconnect from the current WiFi network

  airport -z
  

scutil

• Get the computer's name

  scutil --get ComputerName
  

• Set the computer's name

  scutil --set ComputerName "Tommy's MacBook Pro"
  

• Get the host name

  scutil --get HostName
  

• Set the host name

  scutil --set HostName "nova"
  

• Get the localhost name (used for Bonjour)

  scutil --get LocalHostName
  

• Set the localhost name (used for Bonjour)

  scutil --set LocalHostName "nova"
  

tmutil

• If you have a Time Capsule, you can use the tmutil utility to interface with Time Machine from your terminal.

• Backups are stored in the following location:

  tmutil latestbackup
  

  /Volumes/Time Machine Backups/Backups.backupdb/My Macbook Pro/2019-08-07-061700
  /Volumes/Time Machine Backups/Backups.backupdb/My Macbook Pro/2019-08-07-061700
  

• Turn on Time Machine

  tmutil enable
  

• Turn off Time Machine

  tmutil disable
  

• Start backing up to the Time Capsule

  tmutil startbackup
  

• Stop backing up to the Time Capsule

  tmutil stopbackup
  

Speeding Up Time Machine Backups

If you are having trouble because time machine is taking too long, there's a way to speed up the pace of the back-up.

• Enabling speedy backups (by disabling priority filtering)

  sudo sysctl debug.lowpri_throttle_enabled=0
  

• Disabling speedy backups (by enabling priority filtering)

  sudo sysctl debug.lowpri_throttle_enabled=1
  

The changes made in this command are temporary, they will automatically reset to their default state on their own once the computer has been rebooted.

Saving Local Snapshots

By default, Time Machine will create local snapshots, locally stored backup volumes when it can't connect to your Time Capsule.

• Enable Local Snapshots

  tmutil disablelocal
  

• Disable Local Snapshots

  tmutil enablelocal
  

Excluding Certain Files & Folders

By default, Time Machine will back up everything on your drive. You may, however, have data from large directories stored elsewhere. If so, it might be a good idea to exclude that directory from Time Machine's backups, in the interest of saving space.

• Exclude files in the directory ~/Downloads from backups

  tmutil addexclusion ~/Downloads
  

• Exclude the directory path ~/Downloads from backups

  tmutil addexclusion -p ~/Downloads
  

• Re-enable backups for the directory (and path) ~/Downloads

  tmutil removeexclusion ~/Downloads
  

You can also check if a given file, directory, or volume is excluded

• Check if a file is excluded

  tmutil isexcluded ~/Downloads
  # => [Included] /Users/austin/Downloads
  # => [Included] /Users/austin/Downloads
  

• See an exhaustive list of what's being ignored

  sudo mdfind "com_apple_backup_excludeItem = 'com.apple.backupd'"
  

• Restore files to their previous state

  tmutil restore
  

It's pretty hard to reliably exclude things using the native CLI tools. I've heard that asimov is a great tool to reduce the size of time machine backups.

Create User from Command Line

Adding a new user to a Mac computer from a Terminal window requires you to define the user’s name, set a password, create the user’s home directory and configure their system permissions.

1. Create a user named tommy

   dscl . create /Users/tommy
   

2. Set tommy's shell to /bin/zsh

   dscl . create '/Users/tommy' UserShell '/bin/zsh'
   

3. Set Tommy's have the home directory /Users/tommy

   dscl . create '/Users/tommy' NFSHomeDirectory '/Users/tommy'
   createhomedir -u tommy -c
   

4. Set tommy's RealName to Tommy Trojan

   dscl . create '/Users/tommy' RealName 'Tommy Trojan'
   

5. Give tommy a UID number, (for instance, 502)

   dscl . create '/Users/tommy' UniqueID 502
   

6. Give tommy the primary group ID of 20 (the default for the staff group on macOS)

   dscl . create '/Users/username' PrimaryGroupID 20
   

7. Give tommy the password fighton

   dscl . passwd /Users/tommy 'fighton'
   

8. Add tommy to the list of user's that can be logged into with ssh

   dseditgroup -o edit -t user -a tommy com.apple.access_ssh
   

9. Optionally add tommy to the list of admin users on the computer

   dseditgroup -o edit -d tommy -t user admin
   

Hidden Users

• Allow the creation of secret users, hidden if their UID is 500 or lower

  sudo defaults write /Library/Preferences/com.apple.loginwindow Hide500Users -bool YES
  

• Make the user tommy a hidden user

  # Enabling hidden status
  sudo dscl . create '/Users/tommy' IsHidden 1
  
  # Disabling hidden status
  sudo dscl . create '/Users/tommy' IsHidden 0
  

• Disable the Other... user from appearing in the login screen

  sudo defaults write /Library/Preferences/com.apple.loginwindow SHOWOTHERUSERS_MANAGED -bool false
  

• Add tommy to the list of users hidden on the login screen

  sudo defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array-add "tommy"
  

• Hide the public share folder for the user whose long name is Tommy Trojan

  sudo dscl . delete "/SharePoints/Hidden Tommy Trojan's Public Folder"
  

• Force the user tommy to set a new password

  sudo dscl . passwd '/Users/tommy' ''
  sudo pwpolicy -u username -setpolicy 'newPasswordRequired=1'
  sudo rm -r ~tommy/Library/Keychains/*
  sudo rm -r ~tommy/Library/Keychains/*
  

• Get a list of all users short names

  sudo dscl . list /Users
  

• Get detailed info on a particular user

  sudo dscl . read /Users/<username>
  

• Get a specific value from a user

  dscl . read /Users/<username> <key>
  

• Get detailed info on all users

  dscl . readall /Users
  

• Get a specific value from all users

  dscl . readall /Users <key>
  

• Get concise information about all users

  dscl . ls /Users
  

• Get all of the groups that user root is associated with

  dscl . search /Groups GroupMembership 'root'
  

• Get the name os all of the groups

  dscl . ls /Groups
  

• Check if the user tommy is a member of the group admin

  dseditgroup -o checkmember -m 'tommy' 'admin'
  

• Add the user tommy to the group admin

  dseditgroup -o edit -a 'tommy' -t user 'admin'
  

• Change a user's information

  # [ macOS ]
  sudo dscl . change /Users/austin RealName 'Austin Traver' 'Fake Name'
  # confirming the change
  finger austin
  # reverting the chang
  sudo dscl . -change /Users/austin RealName 'Fake Name' 'Austin Traver'
  sudo dscl . -change /Users/austin RealName 'Fake Name' 'Austin Traver'
  

• Remove tommy from the list of users who are members of the admin group

  dseditgroup -o edit -d 'tommy' -t user 'admin'
  

sysadminctl

• Create a user guest with limited permissions

  sysadminctl -addUser guest -fullName 'Tommy Trojan' -UID 404 -shell /bin/zsh -home /Users/guest
  

  # Use the user 'billy' and his password 'gobruins' to escalate privileges
  sysadminctl -adminUser 'billy' -adminPassword 'gobruins' \
    -addUser 'tommy' \
    -password 'fighton' \
    -fullName 'Tommy Trojan' \
    -UID 502 \
    -shell /bin/zsh \
    -home /Users/tommy
  

  # Create the home directory for 'tommy'
  sudo createhomedir -c
  

• Add a user's password to those capable of unlocking the FileVault at boot

  # Use the existing admin account 'billy' whose password is 'gobruins'
  # to allow the new admin account 'tommy' to login with the 'fighton' password
  sysadminctl -adminUser 'billy' -adminPassword 'gobruins' -secureTokenOn 'tommy' -password 'fighton'
  

fdesetup

• Restart the computer, but bypass FileVault

  sudo fdesetup authrestart
  

Single User Mode

• Reboot the computer into single user mode

  sudo launchctl reboot -s system
  

Power Sound

• Play the audio file that stores the "device is charging" chime.

  afplay /System/Library/CoreServices/PowerChime.app/Contents/Resources/connect_power.aif
  

System Integrity Protection

If you need to make changes to the file system, it might require disabling system integrity protection. By default, the following directories are protected:

1. /System
2. /usr
3. /bin
4. /sbin
5. /var

There are three directories that are not protected:

1. /Applications
2. /Library
3. /usr/local

• Disabling system integrity protection

  csrutil disable
  

• Enabling system integrity protection

  csrutil enable
  

• Checking system integrity protection

  csrutil status
  

Configuring the Login Page

• Show additional info by clicking the clock in the top-right corner

  sudo defaults write /Library/Preferences/com.apple.loginwindow AdminHostInfo IPAddress
  

• Adding a welcome message to the login page

  # [ Adding the message ]
  sudo defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText -string 'Welcome back'
  
  # [ Removing the message ]
  sudo defaults delete /Library/Preferences/com.apple.loginwindow LoginwindowText
  

• Adding a script to run at login

  sudo defaults write com.apple.loginwindow LoginHook /path/to/script
  

• Adding a graphic+text banner to appear upon login

  sudo cp ./banner /Library/Security/PolicyBanner
  

• Disable buttons on the login page

  sudo defaults write /Library/Preferences/com.apple.loginwindow ShutDownDisabled -bool true
  sudo defaults write /Library/Preferences/com.apple.loginwindow RestartDisabled -bool true
  sudo defaults write /Library/Preferences/com.apple.loginwindow SleepDisabled -bool true
  sudo defaults write /Library/Preferences/com.apple.loginwindow SleepDisabled -bool true
  

• Reenable buttons on the login page

  sudo defaults write /Library/Preferences/com.apple.loginwindow ShutDownDisabled -bool false
  sudo defaults write /Library/Preferences/com.apple.loginwindow RestartDisabled -bool false
  sudo defaults write /Library/Preferences/com.apple.loginwindow SleepDisabled -bool false
  sudo defaults write /Library/Preferences/com.apple.loginwindow SleepDisabled -bool false
  

• Disable the user icons from the login page (this sets the "username & password" format as the default for the login page)

  sudo defaults write /Library/Preferences/com.apple.loginwindow SHOWFULLNAME -bool true
  

diskutil

Something learned from man hdiutil: /dev/rdisk nodes are character-special devices, but are "raw" in the BSD sense and force block-aligned I/O. They are closer to the physical disk than the buffer cache. /dev/disk nodes, on the other hand, are buffered block-special devices and are used primarily by the kernel's filesystem code. In layman's terms /dev/rdisk goes almost directly to disk and /dev/disk goes via a longer more expensive route

• View available storage devices

  diskutil list
  

• Erase a hard drive's partitions

  sudo diskutil partitionDisk /dev/disk2 1 MBR "Free Space" "%noformat%" 100%
  

• Copy image to a new hard drive

  diskutil unmount /dev/disk2s1
  sudo dd bs=1M if='/path/to/file.img' of='/dev/rdisk2' conv=sync
  sudo dd bs=1M if='/path/to/file.img' of='/dev/rdisk2' conv=sync
  

• Copy the current hard drive into an image

  # Exporting an SD card save
  sudo dd bs=4M if=/dev/sdb of=raspbian.img
  
  # Importing an SD card save
  sudo dd bs=4M if=raspbian.img of=/dev/sdb
  

• Eject a device

  sudo diskutil eject /dev/rdisk2
  

• Enable vpn connection on port 3340

  kill $(lsof -ti :3340) &> /dev/null
  ssh -fNCD 3340 'ssh://bastion@52.52.124.230:22'
  networksetup -setsocksfirewallproxystate Wi-Fi on
  return 0
  return 0
  

• Disable vpn connection on port 3340

  kill $(lsof -ti :3340) &> /dev/null
  networksetup -setsocksfirewallproxystate Wi-Fi off
  return 0
  

macOS Books

New to macOS Catalina is the Books application, which provides a cleaner interface for handling audiobooks on your Mac.

• The Books app stores audiobook files in ~/Library/Containers/com.apple.BKAgentService/Data/Documents/iBooks/Books/Audiobooks

• Keep Books in a more convenient folder:

  ln -s ~/Library/Containers/com.apple.BKAgentService/Data/Documents/iBooks/Books ~/Books
  

macOS Notes

• Notes are stored in a sqlite database, located on your computer at ~/Library/Containers/com.apple.Notes/Data/Library/Notes/

Printing

• Scan for printers on the network that support the IPP protocol

  dns-sd -Z _ipp._tcp .
  

• Scan for hosts on the network that have enabled login via the SSH protocol.

  dns-sd -Z _ssh._tcp .
  

• Ping the printer to see if it responds

  ping BRN3C2AF4C9463F.local
  

• Setup the printer, giving it the name Brother

  # `-p 'Brother'`: Name the printer "Brother"
  # `-E`: Use TLS encryption when communicating across the network
  # `-v 'ipp://brother.local'`: Print to the URI `<ipp://brother.local>`
  # `-m 'everywhere'`: Use the IPP protocol
  lpadmin -p 'Brother' -E -v 'ipp://brother.local' -m 'everywhere'
  

• Make this printer the default

  lpoptions -E -d 'Brother' -o sides=two-sided-long-edge
  # Creates ~/.cups/lpoptions with one line: "Default Brother sides=two-sided-long-edge"
  

  • -p 'Brother': Name the printer "Brother"
  • -E: Use TLS encryption when communicating across the network
  • -d: Make this the default printer
  • -o: Set the option sides to two-sided-long-edge

• Print a file

  lp ~/path/to/file.pdf
  

• Check the current printer configurations

  lpstat -v
  

Virtual Network Computing VNC

Virtual Network Computing, or VNC, is more commonly known as Screen Sharing, as this is the name of the application used for VNC on macOS. Your computer listens for VNC connections on port 5900, and you can use the <vnc://user@host.net> syntax to reach a particular user at a particular address.

• Launching a Screen Share from the terminal:

  open vnc://tommy@trojan.net
  

• Enabling Screen Sharing from the terminal:

  sudo defaults write /var/db/launchd.db/com.apple.launchd/overrides.plist com.apple.screensharing -dict Disabled -bool false
  

• Disabling Screen Sharing from the terminal:

  sudo defaults write /var/db/launchd.db/com.apple.launchd/overrides.plist com.apple.screensharing -dict Disabled -bool true
  

Icons

You can find icons in some of the following locations:

/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/

You can also find some of the iOS icons in the following places

/System/Library/Extensions/IOSCSIArchitectureModelFamily.kext/Contents/Resources/
/System/Library/Extensions/IOStorageFamily.kext/Contents/Resources/

• Listing all icon files

  print -l /System/Library/**/*/Contents/Resources/*.icns
  

I've made a script that can convert an image into an icon

• Convert PNG file pic.png into ICNS file pic.icns

  iconset=${1%%.*}.iconset
  mkdir -v ${iconset}
  for ((s=16; s<=512; s*=2)); do
      sips -z ${s} ${s} ${1} -o ${iconset}/icon_${s}x${s}.png
  done
  for ((s=16; s<=256; s*=2)); do
      sips -z ${s} ${s} ${1} -o ${iconset}/icon_${s}x${s}@2x.png
  done
  cp ${1} ${iconset}/icon_512x512@2x.png
  iconutil -c icns ${iconset}
  rm -R ${iconset}
  

Filetype Conversion for Printing

• Convert a text file to PostScript

  cupsfilter -m 'application/postscript' file.txt > file.ps
  

• Convert a text file to PDF

  cupsfilter -m 'application/pdf' file.txt > file.pdf
  

Defaults

defaults is a powerful command. defaults a tool to utilize when exporting and importing settings across machines

• Display file extensions

  defaults write NSGlobalDomain AppleShowAllExtensions -bool true
  killall Finder
  

• Prevent file icons from displaying on the Desktop

  defaults write com.apple.finder CreateDesktop -bool FALSE
  killall Finder
  

• Enable quit button for Finder application

  defaults write com.apple.finder QuitMenuItem -bool true
  killall Finder
  

You can prohibit the modification of Finder preferences by selecting Preferences... in the menu bar. As to why you'd want to do this, I have no idea, but here you go:

• Disabling key repeat

  defaults write -g InitialKeyRepeat -int 10
  

• Resetting key repeat to default settings

  defaults write -g InitialKeyRepeat -int 15 # 225 ms
  defaults write -g KeyRepeat -int 2 # 30 ms
  

• Disable modification of Finder preferences

  defaults write com.apple.finder ProhibitFinderPreferences -bool true
  killall Finder
  

Similarly, you could prohibit the Go to folder action in Finder as well, for whatever reason

• Disable Go to folder action in the menu bar:

  defaults write com.apple.finder ProhibitGoToFolder -bool true
  killall Finder
  

If you're tired of .DS_Store files popping up in all of your directories, there's a command to disable them entirely. Before you do however, it's worth nothing that the .DS_Store file is one that contains useful metadata about your file system browsing preferences, such as "Whether to open a folder in 'Application View' or in 'List View'"

• Disable creation of .DS_Store files

  defaults write com.apple.desktopservices DSDontWriteNetworkStores -bool true
  

• Delete dock hiding delay

  defaults write com.apple.dock autohide-delay -float 0
  killall Dock
  killall Dock
  

• Change minimum file size threshold for Mail Drop for macOS Mail

  # 1024 = 1MB
  defaults write com.apple.mail minSizeKB 1024
  defaults write com.apple.mail minSizeKB 1024
  

• Hide the preview of images attached to a message in Mail

  defaults write com.apple.mail DisableInlineAttachmentViewing -bool true
  

TextEdit

• Use plain text as the default in TextEdit instead of rich text

  defaults write com.apple.TextEdit RichText -int 0
  

Misc

• Reset the DNS cache

  sudo discoveryutil udnsflushcaches
  

• Change the cursor's blink rate

  # Enter time in milliseconds
  defaults write -g NSTextInsertionPointBlinkPeriodOn -float 200
  

• Disable the full screen animation

  # Disable slow animation
  defaults write -g NSWindowResizeTime -float 0.001
  

• Disable filenames from including date on screenshots

  defaults write com.apple.screencapture 'include-date' -bool false
  killall SystemUIServer
  

• Disable power button sleeping the system

  defaults write com.apple.loginwindow PowerButtonSleepsSystem -bool false
  

• Treat the help window (the one that shows user manuals) as a normal window link to source

  defaults write com.apple.helpviewer DevMode -bool true
  

• Change the format of the clock in the menu bar (A great tutorial on setting the date and time format)

  defaults write com.apple.menuextra.clock DateFormat 'EEE dd MMM h:mm:ss a'
  

QuickLook

Extending QuickLook Previews

• Adding previews for markdown files

  brew cask install qlmarkdown
  xattr -cr ~/Library/QuickLook/QLMarkdown.qlgenerator
  qlmanage -r
  qlmanage -r cache
  killall Finder
  

• Adding syntax highlighting to code previews

  1. Download the latest release

     https://github.com/sbarex/SourceCodeSyntaxHighlight/releases
     

  2. Sign the application

     xattr -r -d com.apple.quarantine /Applications/Syntax\ Highlight.app
     

  3. Customize themes here

     ~/Library/Application\ Support/Syntax\ Highlight/Themes
     

  4. Customize CSS here

     ~/Library/Application\ Support/Syntax\ Highlight/Styles/global.css
     

Spotlight Search

• ⌘ ↓ Move to next category in search results

• ⌘ ↑ Move to previous category in search results

Boolean Operators

• AND
• OR
• NOT

Search Operators

• Search for results containing Forest but not Gump

  kind:movie Forest -Gump
  

• List of valid options for the kind: operator

  kind:app
  kind:contact
  kind:folder
  kind:image
  kind:movie
  kind:music
  kind:audio
  kind:jpeg
  kind:pdf
  kind:text
  kind:pdf
  kind:preferences
  kind:bookmark
  kind:font
  kind:fonts
  kind:presentation
  kind:mail
  kind:markdown
  kind:chat
  kind:event
  kind:reminder
  kind:reminder
  

author:

• Documents written by Valerie

  author:Valerie
  

date:

• Today

  date:today
  

• Yesterday

  date:yesterday
  

• Before January 1st, 2020

  date:<2020-01-01
  

• After January 1st, 2020

  date:>2020-01-01
  

created:

• Files created after January 1st, 2019

  created:>2019-01-01
  

modified:

• Files modified on March 1st, 2010

  modified:2010-03-01
  

• Files modified before 2018

  modified:<2018
  

weather:

• View the weather in Cupertino

  weather:cupertino
  

• View the definition of wizard

  define:esoteric
  

bitrate:

• View files with a 128kbps bitrate

  bitrate:128
  

iso:

• View pictures with an ISO speed higher than 400

  iso:>400
  

wiki:

• View the wikipedia entry for the topic boolean

  wiki:boolean
  

Searching for messages in Mail

Spotlight by default searches through mail as well, so to find a message, you can retrieve it from Spotlight, without even opening the Mail application.

To learn more about searching the Mail app

The Apple support article that covers how to search for emails in Mail on Mac is not sufficiently comprehensive in my opinion, so I've added more concrete instances of valid search operators in the examples found below.

• Search for all mail sent to: "Tommy Trojan"

  to:"Tommy Trojan"
  to:ttrojan@usc.edu
  

• Search for all mail received from "Billy Bruin"

  from:"Billy Bruin"
  from:bbruin@ucla.edu
  

• Search for all mail with subject: "Secret Recipe"

  subject:"Secret Recipe"
  

• Search for all mail whose subject contains both secret and recipe

  subject:secret subject:recipe
  

• Search for all mail from 2018 and earlier

  • With calendar format set to ISO 8601

  date:2018-12-31
  

• Search for mail between 2017 and 2019 (note the range is not inclusive)

  date:2017-2020
  

Type to:recipient@example.com to find all sent mail addressed to a specific recipient at a specific domain. The subject search operator limits the search results to the contents of email subject lines.

Type subject:cookie in the search field to return all emails with the word "cookie" in the subject line. Type subject:"cookie recipe" to find all mail with the phrase "cookie recipe" in the subject line. Type subject:cookie subject:recipe to find all mail with both "cookie" and "recipe" in any order in the subject line.

Spotlight Siri Knowledge

Siri uses natural language processing (NLP) to identify good matches for searches that don't use search operators. Some useful examples are included below:

• Get the score of the Sharks vs Ducks game

  sharks vs ducks
  sharks game
  sharks game
  

• View the wikipedia entries matched by Grease

  wiki Grease
  

• View the score of the Yankees game

  score Yankees
  

• View the schedule of the Yankees

  schedule Yankees
  

• View the schedule of the Giants (Football) team

  Giants football schedule
  

• View the conversion rate of USD to RMB

  1 USD in RMB
  

• Convert temperature from 58 degrees Fahrenheit to Celsius

  58 F to C
  

• Convert temperature from 58 degrees Fahrenheit to Kelvin

  58 F to K
  

• View the stock price for symbol V

  V stock
  

Disable Spotlight Index of Network Drives

• Have Spotlight ignore every external volume

  sudo defaults write /Library/Preferences/com.apple.SpotlightServer.plist ExternalVolumesIgnore -bool True
  

• Have Spotlight ignore, by default, each new network volume it encounters, from here on out:

  sudo defaults write /Library/Preferences/com.apple.SpotlightServer.plist ExternalVolumesDefaultOff -bool True
  

Safari Web Extensions

To convert Firefox web extensions into Safari web extensions, you'll need Xcode 12, and the command-line tools that accompany it

• Converting the extension from a Firefox extension into a Safari extension

  xcrun safari-web-extension-converter [options] ./path/to/extension
  

CalDAV Synchronization

You can control which calendars in your Google Calendar to share with iCloud by going to Google Calendar's page about sync settings

URL Schemes

• Print out all supported URL schemes

  /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -dump | grep -B6 'bindings:.*:'
  

Compressor

The Compressor application is part of the iWork premium set of apps, which includes applications like "Logic Pro" and "Final Cut Pro".

• Using Compressor from the command line

  alias compressor='/Applications/Compressor.app/Contents/MacOS/Compressor'
  

Other Useful Commands

• Check the battery life from your terminal

  pmset -g batt
  

• Disable sleep for one session

  pmset noidle &!
  

• Disable sleep entirely

  sudo systemsetup -setcomputersleep Never
  

• Immediately put the computer to sleep

  pmset sleepnow
  

• Schedule for the computer to regularly wake up (or boot) on weekdays @ 7:45AM

  pmset repeat wakeorpoweron MTWRF 07:45:00
  

• Schedule for the computer to sleep on 12/24 @ 8:00AM

  pmset schedule sleep "12/24/2019 08:00:00"
  

• Schedule for computer to sleep in 1 hour:

  sudo systemsetup -setcomputersleep 60
  

• Check when the computer is scheduled to sleep

  sudo systemsetup -getcomputersleep
  

• Schedule for the computer to wake on 12/24 @ 8:00PM

  pmset schedule wake "12/24/2019 20:00:00"
  

• Restart the computer immediately

  # Option 1
  sudo reboot now
  
  # Option 2
  sudo shutdown -r now
  

• Shut down the computer immediately

  sudo shutdown now
  

• Dangerously shut the computer down immediately

  sudo halt
  

AppleScript

You can trigger AppleScript from a web link using the applescript URL scheme.

For instance, this is the AppleScript to print hello world on a user's computer.

applescript://com.apple.scripteditor?action=new&script=display%20dialog%20%22hello%20world%22

• Create an alert window that shows a dialog and presents the user with two choices

  osascript <<< 'display alert "Do you accept?" buttons {"Cancel", "Yes"}'
  

• Display a notification

  • Simple message

    osascript  <<< "display notification \"${message}\""
    

  • Message with a title

    title='Breaking news'
    message='You are a hacker'
    
    osascript <<< "display notification \"${message}\" with title \"${title}\""
    

  • Message with a title and a subtitle

    title="Breaking news"
    subtitle="No seriously"
    message="You are my sunshine"
    osascript <<< "display notification \"${message}\" with title \"${title}\" subtitle \"${subtitle}\""
    

  • Message with a title and a sound

    title="Quick question"
    message="Did you hear that?"
    osascript <<< "display notification \"${message}\" with title \"${title}\" sound name \"default\""
    

Color Swatches

• Swatches have an extension of .clr and can be found in ~/Library/Colors

  ls ~/Library/Colors
  

  Output

  NSColorPanelSwatches.plist
  Custom.clr
  Custom.clr
  

Screen Capture

I recommend reading Apple's article Take a screenshot on your Mac. I learned something I didn't know. You can hold the ⌥ modifier key while taking a screenshot of a window to prevent the drop shadow from appearing!

Personally, I think the drop shadow is a good touch. If, however, you prefer that drop shadows be disabled by default when taking a screen capture of an application window, you can use the following command.

• Disable drop shadow for application window screenshots:

  defaults write com.apple.screencapture disable-shadow -bool true && killall SystemUIServer
  

FaceTime

When you're on a FaceTime audio call, or any phone call for that matter, your desktop will be presented with a small window in the top-right corner. That window can be bothersome, as it floats on top of of whatever applications you're using. I discovered how it can be hidden:

• Hide the FaceTime window

  pkill -9 FaceTimeNotificationService
  

AirDrop

You can add AirDrop to the dock by visiting the following directory.

/System/Library/CoreServices/Finder.app/Contents/Applications

From there, click and drag the AirDrop.app icon to your dock

You can also drag the iCloud.app icon to your dock as well.

Launchpad

You can change the Launchpad icon grid layout, but it requires some defaults write commands, provided below.

• Set the number of rows in Launchpad

  # Default: 5 rows 
  defaults write com.apple.dock springboard-rows -int 5
  killall Dock
  

• Set the number of columns in Launchpad

  # Default 7 columns
  defaults write com.apple.dock springboard-columns -int 7
  killall Dock
  

• Restore the default Launchpad app layout

  defaults write com.apple.dock ResetLaunchPad -bool true
  killall Dock
  

• Restore the Launchpad dimensions to its original 5x7 layout

  defaults delete com.apple.dock springboard-rows
  defaults delete com.apple.dock springboard-columns
  killall Dock
  

Feedback Assistant

The Feedback app is available on all iOS devices, even if they aren't running a beta. devices.

To get to it, open up Safari and navigate to the URL applefeedback://

xattr

• Remove the Where from field from video.mp4, which was downloaded using curl

  xattr -d 'com.apple.metadata:kMDItemWhereFroms' video.mp4
  

xcode-select

• Enabling the Xcode Beta command line tools

  sudo xcode-select --switch /Applications/Xcode-beta.app/
  

sips

Mac has an inbuild tool for editing images called sips, which is an abbreviation for scriptable image processing system. You can learn about it here, but I encourage you to check out man sips and sips --help as well.

• Convert PNG file to JPEG format

  # Valid formats are as follows:
  # jpeg | tiff | png | gif | jp2 |
  # pict | bmp | qtif | psd | sgi | tga
  sips -s format jpeg './image.png' -o './image.jpeg'
  

• Rotate PNG file 90 degrees

  sips -r 90 'image.png'
  

• Flip an image horizontally

  sips -f horizontal 'image.png'
  

• Flip an image vertically

  sips -f vertical 'image.png'
  

• Crop an image to HEIGHT by WIDTH

  sips -c HEIGHT WIDTH 'image.png'
  

• Resize image to updated dimensions HEIGHT by WIDTH. (Note: this may alter the actual aspect ratio)

  sips -z HEIGHT WIDTH 'image.png'
  

• Resize image to a maximum height or width DIMENSION, preserving the existing aspect ratio

  sips -Z DIMENSION 'image.png'
  

• Get the dimensions (width and height) of an image

  sips -g pixelWidth -g pixelHeight IMAGE
  

Daemons, Agents, and Automation

daemon : A computer program that runs as a background process.

agent : A program that acts on behalf of another program, or on behalf of another user.

user agent : a daemon specific to a logged-in user that only executes while that user is logged in.

process identifier : a number used by most operating system kernels to uniquely identify an active process.

The original daemon is init, which has process identifier #1 because it is the first process started during the booting of the computer system.

macOS has a more robust alternative to cron which allows daemon processes to be triggered on a systematic fashion. Using the launchctl (launch control) command, you can create daemon processes that will automatically run by the system.

These files take the form of plist files and are found in several system directories:

• /Library/LaunchAgents
• /Library/LaunchDaemons
• /System/Library/LaunchAgents
• /System/Library/LaunchDaemons
• ${HOME}/Library/LaunchAgents

If you write or install personal plist files, they will ideally go in the home directory. A good example file to begin understanding the syntax can be located in /System/Library/LaunchDaemons/ssh.plist, which is the file used to launch the ssh daemon server that listens for incoming ssh connections.

Specifying privacy-sensitive files and folders in a launchd property list might not work as expected and prevent the service from running. Having Program or Program Arguments pointing to an executable in a privacy sensitive location is currently allowed, but may be restricted in a future release.

To comply with the new privacy protections, resources for a launchd service must be stored in locations that aren't privacy sensitive. If necessary, the app can set up resources during its execution rather than using launchd property list keys, making it possible to grant the app access using System Preferences > Security & Privacy > Privacy. The following launchd property list keys are affected: Keep Alive, Path State, Queue Directories, Sockets, Sock Path Name, Standard Error``Path, Standard In Path, Standard Out Path, and Watch Paths.

If you're setting up processes in /Library/LaunchDaemons, which are run as the root user, then make sure to set the file permissions appropriately using chown root:wheel <file> and chmod 644 <file>

• View launchctl information about a daemon process by its PID:

  sudo launchctl profinfo <PID>
  

• View information about all services pertaining to a user's UID:

  launchctl print user/$UID
  

• View information about a particular running service under a user's UID:

  # ~/Library/LaunchAgents/com.tommy.foo.plist
  launchctl print com.tommy.foo
  

• For all daemon processes owned by the current user, print true if they are disabled

  launchctl print-disabled user/$UID
  

launchctl has changed for the better in 10.11.4

Type the command without arguments to get the help. You'll see new domains to search and new commands.

• Printing the system root

  launchctl print system
  

• Printing details about a particular service within the root domain

  launchctl print system/com.example.service
  

For your processes: if it's not in the system domain it's probably in the domain of that particular user.

• Checking the domain of a particular user

  launchctl print user/<uid>/
  launchctl print user/<uid>/com.example.useragent
  

However, since you'll be logged into the GUI, you might want to check the domain of the GUI, which is kept separate.

• Checking the domain of the GUI

  launchctl print gui/<uid>
  launchctl print gui/<uid>/com.example.service
  

• GUI domains are for processes that apply to a user interface.

• User domains are for processes that invoke daemons that only apply to a particular logged-in user.

• System domains are for system daemon processes, and apply to all users within that system.

To learn more, read man launchctl or read Apple's article about Creating Launch Daemons and Agents

• Enable a daemon service

  launchctl enable user/$UID/com.tommy.foo
  

• Disable a daemon service

  launchctl disable user/$UID/com.tommy.foo
  

• Launch a daemon service

  launchctl kickstart
  

• Launch any executable file with arguments as a launchctl

  launchctl submit -l -- /path/to/executable 'arg1' 'arg2' 'arg3'
  

I wasn't sure where the best place to put this is, but it will link the latest version of GCC installed by Homebrew into /usr/local/bin, while also removing the version number suffixed to the filename by Homebrew's installation formula.

# Choose the directory containing the latest version of GCC
# as indicated by the highest number suffixed to 
# the filepath of the package directory
print -v version /usr/local/opt/gcc@<->(n[-1])
version=${version#*@}
for file in /usr/local/opt/gcc@${version}/bin/*-${version}(*); do
    tail=${file:t}
    ln -sf ${file} /usr/local/bin/${tail%-*}
done

If symbolic links are overkill for you, then check this out. The snippet below will hash the executable corresponding with each file, which zsh will expand each command to when called, and will do this up until the next point that the path is modified by the shell. At that point, these hashed commands will be rehashed, meaning the location specified in the hash command's specified directory will have its executable overwritten and replaced by the executable in the foremost directory in the path containing an executable with a matching name.

print -v version /usr/local/opt/gcc@<->(n[-1])
version=${version#*@}
for file in /usr/local/opt/gcc@${version}/bin/*-${version}(*); {
    tail=${file:t}
    hash ${tail%-*}=${file}
}

iMessage

This isn't written down anywhere, so I'm writing it here: You can send message effects on the macOS Messages application with a keyboard shortcut: ⌘ ⇧ A