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I've downloaded some .jar files from the internet and want to use them under Mac OS X. But the OS seems to have tagged them with the extended attribute com.apple.quarantine (no indication of this until I noticed the "@" in the ls -l and figured out how to use ls -l@) -- apparently because they have been downloaded from the internet. What's the right way to deal with this?

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5 Answers 5

up vote 29 down vote accepted

This attribute is added so that it can ask for user confirmation the first time the downloaded program is run, to help stop malware. Upon confirmation the attribute should be removed and then the program will run normally.

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ahhhhhh.... ok that makes sense. So it's a contract between browser implementations that save files, and the OS and/or Java when it runs executables. –  Jason S Aug 23 '09 at 22:02

You don't have to deal with it. Open it and OS X will ask for your permission. Or like richard suggested, delete it using something like:

xattr -d com.apple.quarantine my_jar.jar

To do this automatically for any downloaded file you can attach a folder action to the download folder, like described on macosxhints.com in 10.5: Remove the 'downloaded file' warning flag.

And the following was posted on macosxhints.com a long time ago, for Safari: 10.5: Disable the 'downloaded from internet' file warning, claiming one can remove VerifiedDownloadPlugin.plugin from /Library/Internet Plug-Ins. I did not test that.

As an aside: sometimes one needs to start a single program multiple times on a Mac. That can be done using cd /Applications/some-application/ followed by open -n "Application Name.app". This really needs the .app suffix; running open -n "Application Name" might get one GateKeeper stopping access:

"Application Name" can't be opened because it is from an unidentified developer.

Your security preferences allow installation of only apps from the Mac App Store and identified developers.

Above, even removing the extended attribute com.apple.quarantine does not fix that, but using the .app suffix works just fine.

(I am not advising anyone to actually get rid of the security measures.)

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You can disable the warnings permanently with defaults write com.apple.LaunchServices LSQuarantine -bool false. It also disables the Gatekeeper dialogs even if you haven't allowed applications downloaded from anywhere in System Preferences.

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I found the following command

find Application.app | while read l; do echo $l; xattr -d com.apple.quarantine "$l"; done

very helpful when trying to get rid of the attribute. Note the double quotes around $l – you need them if your apps folder contains files with a blank in their name.

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You could also use xattr -rd com.apple.quarantine Application.app. –  ؘؘؘؘ Sep 22 '12 at 9:22
 xattr -d com.apple.quarantine /path/to/file
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Don't use sudo when you don't have to. –  Sidnicious Aug 25 '09 at 15:17
Edited the answer to remove 'sudo'. –  Richard Hoskins Aug 25 '09 at 16:10
How do you do this recursively to all files in a directory? –  landon9720 Mar 27 '12 at 19:50
@landon9720 - The (currently) below answer has a comment that allows you to instruct xattr to work recursively over contents of a supplied directory –  user66001 Jul 23 '13 at 1:45

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