Basically every file downloaded from the internet is tagged by the OS depending on its file type. If the download is an application or script, the OS will warn you with the above message when you first try and open it. Fine if you are opening one or two files, but not if you are trying to open up 20+ files at a time.

There is some reasoning behind this security feature, but I can’t help think that Apple should have included a way to turn it off or at least configure what file types the user deems ’safe’ or ‘unsafe’.

After Googleing for a solution I discovered two options. The first is by Henrik (Lift the Leopard download quarantine) is a simply Apple Script folder action that you apply to your Downloads folder. Every time a file is downloaded the Apple Script removes the ‘unsafe’ tag from it and thus banishes the warning message. The only problem I can see with the script is that is dose not work its magic on files within sub-folders.

The second is by Lazeez (Changing the system’s default settings for html files (safe)) and is my preferred solution. Basically you need to create a file called com.apple.DownloadAssessment.plist with a list of the file types you consider ’safe’, you then need to save it to the ~/Library/Preferences folder, log-out or reboot to activate the changes, and no more warning messages!

The file looks like this:-

<?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>LSRiskCategorySafe</key>
<dict>
	<key>LSRiskCategoryContentTypes</key>
<array>
	<string>public.html</string>
	<string>public.php-script</string>
</array>
</dict>
</dict>
</plist>

You can see I have added two strings, public.html and public.php-script this allows me to open both .html and .php files without the warning. A full list of file types can be found on the Apple Developer site: System-Declared Uniform Type Identifiers.

To add more, simply add in <string>file.type.here</string> (The file type Identifier)

I hope this helps other Leopard users as much as it has helped me – as any unnecessary clicks can really start to slow a work flow down.