Disabling Snow Leopard’s “Are you sure you want to open it?” dialogues

After upgrading to Snow Leopard, I noticed that my tip for disabling the system's “Are you sure you want to open it?” messages for downloaded files no longer did the job. It took a bit of digging, but eventually I figured out that this was due to changes Apple made to the uniform type identifier (UTI) hierarchy.

Whereas in Leopard the public.item type was the base of the entire UTI hierarchy, in Snow Leopard it's the base only for the physical hierarchy (which appears to contain only filesystem-related types). As far as I can tell, there is no longer a single common ancestor for all UTI's, so com.apple.DownloadAssessment.plist must list each root type explicitly. Here's an updated version that does just that:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
   "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <dict>
    <key>LSRiskCategoryNeutral</key>
    <dict>
      <key>LSRiskCategoryContentTypes</key>
      <array>
        <string>public.item</string>
        <string>public.content</string>
        <string>public.database</string>
        <string>public.calendar-event</string>
        <string>public.message</string>
        <string>public.contact</string>
        <string>public.archive</string>
        <string>public.url-name</string>
        <string>public.executable</string>
      </array>
    </dict>
  </dict>
</plist>

As before, put the file under Library/Preferences in your home directory. Then, log out and back in, and your Mac should be obnoxious-warning free.

Tags: apple
Wed, 09 Dec 2009 05:33 UTC

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