Running an AS droplet from Terminal

You can use another AppleScript that tells Finder to open files with the droplet application.

For example save this script as /Applications/droplet.app in AppleScript Editor:

on open a
    repeat with f in a
        say POSIX path of f
    end repeat
end open

Then run:

osascript -e 'on run {f}' -e 'tell app "Finder" to open POSIX file f as alias using POSIX file "/Applications/droplet.app"' -e end /bin/test

To open multiple files, convert the list of arguments to a list of file objects:

osascript -e 'on run a
set l to {}
repeat with f in a
set l to l & POSIX file f
end
tell app "Finder" to open l using (POSIX file "/Applications/droplet.app")
end' ~/*

Alternatively, create the droplet application with Automator instead of AppleScript Editor:

Then run open -a droplet2 /bin/test.

The run handler is also used for files dropped on the application. A handler named open does not have any special meaning.

One drawback of using Automator applications is that there is a relatively long delay before they are run.