Use Network Link Conditioner from command line

throttle.applescript

-- https://stackoverflow.com/questions/34876073/switch-network-link-conditioner-profiles-from-console-script/38991769
set mode to system attribute "mode"

tell application "System Preferences"
  activate
  set current pane to pane "com.apple.Network-Link-Conditioner"
  delay 1
end tell

tell application "System Events"
  tell process "System Preferences"
    if mode is equal to "OFF"
        tell window "Network Link Conditioner"
          click button "OFF"
        end tell
      else
        tell window "Network Link Conditioner"
        click button "ON"
        tell group 1
          click pop up button 1
          click menu item mode of menu 1 of pop up button 1
        end tell
      end tell
    end if
  end tell
end tell

tell application "System Preferences" to quit

-- http://apetronix.com/find-pane-id-for-system-preferences-app/
-- tell application "System Preferences"
-- 	set CurrentPane to the id of the current pane
-- 	set the clipboard to CurrentPane
-- 	display dialog "Current Pane ID: " & CurrentPane & return & return & "Pane ID has been copied to the clipboard."
-- end tell

Usage:

# Set mode to 3G throttling...
mode=3G osascript throttle.applescript

# Set mode to "Very Bad Network"...
mode="Very Bad Network" osascript throttle.applescript

# Turn off throttling...
mode=OFF osascript throttle.applescript

Add some aliases to your .zshrc file for convenience:

alias throttle:on="mode=3G osascript throttle.applescript"
alias throttle:off="mode=OFF osascript throttle.applescript"