Leopard's ls

[Derek Chesterfield]

On 9 Nov 2007, at 16:27, LuKreme wrote:

> From the man page [of ls]:
>
> If the file or directory has extended attributes, the permissions  
> field printed by the -l option is followed by a '@' character.   
> Otherwise, if the file or directory has extended security  
> information, the permissions field printed by the -l option is  
> followed by a '+' character.
>
> so, what exactly do 'extended attributes' and 'extended security  
> information' mean? Are we talking about ACLs?

Extended security information is indeed ACLs. You can view what ACLs a  
file has by doing 'ls -le'. You can also view and set ACLs in Finder's  
Get Info panel for the file.

Extended attributes are arbitrary bits of data associated with a file,  
and are set by the application. You can see the attribute keys using  
'ls -l@'. You can't see the values though; extended attributes are  
application-defined, so it is not usually useful to be able to read  
them! Finder sets some, which you will see with the  
com.apple.FinderInfo key. The number is the size of the attribute.  
Safari also sets some to keep track of files which were downloaded  
etc., e.g. com.apple.quarantine.