meyerweb.com

One of the things that I’ve found mind-bendingly annoying about Leopard (besides its complete refusal to allow classic window management) is the “this file was downloaded from the internet, are you sure you want to open it?” dialog box. Yes, damn it: I just downloaded the file with the express intent of opening it. Stop bothering me. Keep it up and I might mistake you for PC.

What’s even worse is that the dialog requires mouse input to get past. It would be just within the limits of acceptability if the dialog buttons responded to keyboard input; if I could hit command-O or something to invoke “Open”, then I’d probably keep the safeguard in place, because I could just charge past it with a quick twitch of the fingers. Since I can’t, I want it gone. And of course there’s no “don’t ask me again” checkbox to tick.

After a plea on Twitter, I got pointers to a couple of ways to disable this annoyance (as well as a ton of “oh God, I hate that too; let me know if you find an answer!” replies). The first way is done as a Folder Action. For a variety of reasons, I’m not that thrilled by folder actions, so I gave it a pass. The other approach is to write your own preference file. Ah, much better! (Why is this better? I don’t know. It just intuitively feel like the better approach to me.)

Now, one way is to just disable the warning for all public.item files—which is to say, every type of file. I was tempted, but it turns out there’s a finer grain that can be applied: listing specific file types to be ignored. Better still! That way I can switch this off for the file types that I download all the time, like HTML files, and keep the safeguard in place for file types I almost never download, like executable scripts.

Doing this means you need a list of OS X’s Uniform Type Identifiers, so I dug around to find that listing, which appears to have moved in the not-too-distant past. Here’s the preference file I’ve put together with that listing as a guide. This file lists all of the file types I don’t want to be nagged about.

<!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.text</string>
        <string>public.plain-text</string>
        <string>public.xml</string>
        <string>public.archive</string>
        <string>public.image</string>
        <string>public.audiovisual-content</string>
        <string>public.font</string>
      </array>
    </dict>
  </dict>
</plist>

I led with public.text because it encompasses not just regular text files, but HTML files as well; public.xml appears to cover XHTML, though I’m not 100% sure where those files fall. public.audiovisual-content covers all audio and video files, as you might guess. There are probably a few other types I’ll add over time, as I encounter enough resistance on certain types of files that I don’t need to be safeguarded. I’ll probably never add public.script or public.executable to the list; personally, I prefer to be warned about that sort of stuff.

To make the magic happen, save the above file (or your own variation) as ~/Library/Preferences/com.apple.DownloadAssessment.plist. Then log out of and back into your account. Finito.

So if you’d like to get your Mac to be less of a nag about opening downloaded files, there’s how. As the links above show, I’m standing on the shoulders of giants here, so my thanks to those who paved the way. I hope that you will be able to benefit from both their work and my small additions thereto.

Update [13 Mar 09]: Potentially very bad news, folks. I just tried this on my 10.5.6 machine and it failed utterly. As did the Folder Action approach. Older versions of Leopard apparently didn’t have this problem. Anyone else seeing the same kind of thing on their machines? If either way is still working for you under 10.5.6, can you tell us which one it is in the comments? Thanks.

Update [18 Mar 09]: Great news, folks. Ben Millett kindly sent me a copy of his working-under-10.5.6 file and I tried it out, and it worked! The difference seems to be that the version I was using was encoded as “Unicode™ (UTF-8, no BOM)” whereas the encoding of the file Ben sent me is “Western (Mac OS Roman)” (both according to BBEdit). So if your copy doesn’t work, check the file encoding. Next I’m going to experiment with adding file extensions, and will report back if I meet with success.