Disable Application Downloaded from Internet Warning in OS X Mountain Lion
To disable the warning, use the xattr delete command:
xattr -d -r com.apple.quarantine /application/path/here
I downloaded Firefox from Chrome and was presented with the "application downloaded from the internet" warning every time I opened Firefox. To get rid of the warning, I ran the following command from the terminal:
sudo xattr -d -r com.apple.quarantine /Applications/Firefox.app
The xattr command manages attributes on files. The -d flag indicates that the com.apple.quarantine attribute should be deleted. The -r flag indicates that the attribute should be removed recursively from all files in the designated directory.
Thanks to Apple Forums: https://discussions.apple.com/message/9424505
Written by Thomas Van Doren
Add your response
and how do i revert this?
I haven't tried to undo this operation, but something like this might work:
xattr -w com.apple.quarantine <the value> <the file(s)>
This assumes the old value is known. The value can be printed with:
xattr -p com.apple.quarantine <filename>
I would probably delete and re-download if I wanted the downloaded content warnings back, though.