See extended attributes with coreutils ls on Mac

You can add extended attributes to coreutils ls. This is based on coreutils-8.22:

***************
*** 59,62 ****
--- 59,64 ----
  #include <wchar.h>

+ #include <sys/xattr.h>
+
  #if HAVE_LANGINFO_CODESET
  # include <langinfo.h>
***************
*** 3056,3059 ****
--- 3058,3062 ----
                              : ACL_T_YES));
            any_has_acl |= f->acl_type != ACL_T_NONE;
+           any_has_acl |= listxattr(f->name, NULL, 0, XATTR_NOFOLLOW);

            if (err)
***************
*** 3811,3814 ****
--- 3814,3819 ----
    if (! any_has_acl)
      modebuf[10] = '\0';
+   else if (listxattr(f->name, NULL, 0, XATTR_NOFOLLOW) > 0)
+     modebuf[10] = '@';
    else if (f->acl_type == ACL_T_SELINUX_ONLY)
      modebuf[10] = '.';

Basically I looked in the OS X ls source to find the logic for printing the @ (the listxattr call) and hooked that into where coreutils ls puts a symbol after the permissions. The three changes are:

1. Including xattr.h
2. Set any_has_acl if any of the listings have extended attributes - this is required so that listings that don't have extended attributes have a space inserted after the permissions to line things up
3. Do the actual check by calling listxattr and conditionally setting the @ symbol - might be worth noting that they way this is written will show only the @ if there are both extended attributes and ACL

The XATTR_NOFOLLOW argument tells listxattr not to follow symlinks. That argument is used in OS X ls.