ブラウザを使わずURLをダウンロード　

applescript

URL Access Scriptingというのを使う

set aPath to (path to desktop folder from user domain as text)
set dPath to aPath & "test.txt" as Unicode text

try
	with timeout of 30 seconds
		tell application "URL Access Scripting"
			activate
			set aURL to "http://google.com"
			download aURL to file dPath with progress
		end tell
	end timeout
on error
	display dialog "Download Error"
end try

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