homebrew-cask/doc/cask_language_reference/stanzas/installer.md

installer

This stanza must always be accompanied by uninstall.

The installer stanza takes a series of key-value pairs, the first key of which must be manual: or script:.

installer manual:

installer manual: takes a single string value, describing a GUI installer which must be run by the user at a later time. The path may be absolute, or relative to the Cask. Example (from little-snitch.rb):

installer manual: 'Little Snitch Installer.app'

installer script:

installer script: introduces a series of key-value pairs describing a command which will automate completion of the install. The form is similar to uninstall script::

key	value
executable:	path to an install script to be run
args:	array of arguments to the install script
input:	array of lines of input to be sent to stdin of the script
must_succeed:	set to false if the script is allowed to fail
sudo:	set to true if the script needs sudo

The path may be absolute, or relative to the Cask. Example (from ransomwhere.rb):

  installer script: {
                      executable: "#{staged_path}/RansomWhere.app/Contents/MacOS/RansomWhere",
                      args:       ['-install'],
                      sudo:       true,
                    }

If the installer script: does not require any of the key-values it can point directly to the path of the install script. Example (from amazon-drive.rb):

installer script: 'Amazon Drive Installer.app/Contents/MacOS/Amazon Drive Installer'