how to remove quarantine from file permissions in os x

Question

I downloaded a .pem file and my Mac OS X (10.8.2) added an @ sign at the end of the file permissions. This is causing file permission issues. I can't seem to remove the quarantine flag. I even tried the command

xattr -d <filename>.pem 

but that didn't work

Solution

xattr -d requires you to specify which attribute you want to remove. You can find this out by listing the file attributes by passing ls the -@ flag as in:

ls -l@ filename

Once you know what the attribute is, you can target it for removal with -d or you can use the following to clear all attributes:

xattr -c filename