81

When doing an ls in a directory I get the following output:

drwxr-xr-x@ 12 xonic  staff    408 22 Jun 19:00 .
drwxr-xr-x   9 xonic  staff    306 22 Jun 19:42 ..
-rwxrwxrwx@  1 xonic  staff   6148 25 Mai 23:04 .DS_Store
-rw-r--r--@  1 xonic  staff  17284 22 Jun 00:20 filmStrip.cpp
-rw-r--r--@  1 xonic  staff   3843 21 Jun 21:20 filmStrip.h

I was wondering what the @ means.

75

It indicates that the file has extended attributes. Use ls -l@ to see them.

You can use xattr to edit these attributes. xattr -h will give you the inline help for it.

24

Off the top of my head, I think is has something to do with the file having extended attributes available. Here's a link to a similar discussion:

http://discussions.apple.com/thread.jspa?messageID=5791060

So if you see a file with an "@" when you do an ls, try doing this:

xattr -l <filename>

That should show you the extended attributes.

You can check xattr's help for more details:

xattr --help
usage: xattr [-l] file [file ...]
       xattr -p [-l] attr_name file [file ...]
       xattr -w attr_name attr_value file [file ...]
       xattr -d attr_name file [file ...]

The first form lists the names of all xattrs on the given file(s).
The second form (-p) prints the value of the xattr attr_name.
The third form (-w) sets the value of the xattr attr_name to attr_value.
The fourth form (-d) deletes the xattr attr_name.

options:
  -h: print this help
  -l: print long format (attr_name: attr_value)

It seems like if you look at the extra attributes with "-l" and then remove them with "-d" it'll probably do what you want. Practice this in a temporary directory somewhere first though and make sure it works ;)

  • Thanks a lot! It would seem that the directory in question was marked as com.apple.quarantine, which is a security measure to protect against dodgy scripts and apps from the net. That can't possibly cause the problem of the directory not listing. :/ I'll look around more and post the solution if I find it. – Constant M Aug 26 '09 at 20:17
20

From the ls(1) man page on Mac OS 10.6.1:

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 (such as an access control list), the permissions field printed by the -l option is followed by a '+' character.

From the available options list:

 -@      Display extended attribute keys and sizes in long (-l) output.

 -e      Print the Access Control List (ACL) associated with the file, if present, in long (-l) output.

These will let you see the value of those extended options. FWIW, ACL info can be set using the same chmod(1) utility you are probably already aware of. :-)

There doesn't appear to be an easy way from the command line to do anything with extended attributes.

  • 2
    Extended attributes can be viewed and manipulated with the xattr command (only available in OS X v10.5 and .6). It doesn't seem to have a man page, but xattr -h will print its internal help. – Gordon Davisson Nov 6 '09 at 20:28
  • xattr now has a man page, and you can use xattr -l file to list all attributes or xattr -p attribute_name file to print a specific attribute. – Lri Aug 14 '13 at 12:09
9

From the man page for ls:

If the -l option is given, the following information is displayed for each file: file mode, number of links, owner name, group name, number of bytes in the file, abbreviated month, day-of-month file was last modified, hour file last modified, minute file last modified, and the pathname.

In addition, for each directory whose contents are displayed, the total number of 512-byte blocks used by the files in the directory is displayed on a line by itself, immediately before the information for the files in the directory.

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 (such as an access control list), the permissions field printed by the -l option is fol-lowed followed lowed by a '+' character.

Use:

ls -la@e

for more information on files or directories with those attributes/information.

8

This is related to extended attributes and access control.

From the man page of sun ls:

The character after permissions is an ACL or extended attributes indicator. This character is an @ if extended attributes are associated with the file and the -@ option is in effect. Otherwise, this character is a plus sign (+) character if a non-trivial ACL is associated with the file or a space character if not.

7

The "@" means that the file has "extended attributes" associated with it.

If you do "ls -@ -l", you can see what attributes there are for each file. You can also do something like "xattr -l pgsql.so" to dump the attributes for a particular file.

Typically they're stuff like old-school FinderInfo, text encoding info, or the "quarantine" info that gives you the "This file was downloaded from the web, are you sure you want to open it?" warning.

  • 1
    Extended attributes are not unique to the mac platform. A number of operating systems support this file-level feature. – Stefan Kendall Jul 14 '10 at 16:46
  • @iftrue: ultimately it's a file system feature, though. – Joey Jul 14 '10 at 17:06
6

From the man page of ls:

The Long Format
[…] If the file or directory has extended attributes, the permissions field printed by the -l option is followed by a '@' character. […]

  • 2
    Note that the '@' can also hide the '+' that would normally be there to indicate that the file/directory has an ACL associated with it. Try 'ls -le@O' -- that'll list xattrs, ACL (if present), and also any flags. – Gordon Davisson Aug 26 '09 at 20:32

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