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       listxattr, llistxattr, flistxattr - list extended attribute names


       #include <sys/types.h>
       #include <attr/xattr.h>

       ssize_t listxattr (const char *path,
                            char *list, size_t size);
       ssize_t llistxattr (const char *path,
                            char *list, size_t size);
       ssize_t flistxattr (int filedes,
                            char *list, size_t size);


       Extended attributes are name:value pairs associated with inodes (files,
       directories,  symlinks,  etc).   They  are  extensions  to  the  normal
       attributes which are associated with all inodes in the system (i.e. the
       stat(2) data).  A complete overview of extended attributes concepts can
       be found in attr(5).

       listxattr  retrieves  the  list  of extended attribute names associated
       with the given path in the filesystem.  The list is the set  of  (NULL-
       terminated)  names,  one after the other.  Names of extended attributes
       to which the calling process does not have access may be  omitted  from
       the list.  The length of the attribute name list is returned.

       llistxattr  is identical to listxattr, except in the case of a symbolic
       link, where the list of names of extended  attributes  associated  with
       the  link itself is retrieved, not the file that it refers to.  list is
       a caller-allocated buffer of size size.

       flistxattr is identical to listxattr, only the open file pointed to  by
       filedes (as returned by open(2)) is interrogated in place of path.

       A  single  extended  attribute name is a simple NULL-terminated string.
       The name includes a namespace prefix - there may be  several,  disjoint
       namespaces associated with an individual inode.

       An  empty  buffer of size zero can be passed into these calls to return
       the current size of the list of extended attribute names, which can  be
       used  to  estimate  the size of a buffer which is sufficiently large to
       hold the list of names.


       The list of names is returned as an unordered array of  NULL-terminated
       character  strings  (attribute names are separated by NULL characters),
       like this:

       Filesystems like ext2, ext3 and XFS which implement  POSIX  ACLs  using
       extended attributes, might return a list like this:


       On  success,  a  positive number is returned indicating the size of the
       extended attribute name list.  On failure, -1 is returned and errno  is
       set appropriately.

       If  the  size of the list buffer is too small to hold the result, errno
       is set to ERANGE.

       If extended attributes are not supported  by  the  filesystem,  or  are
       disabled, errno is set to ENOTSUP.

       The  errors  documented for the stat(2) system call are also applicable


       Andreas  Gruenbacher,  <>  and  the  SGI   XFS
       development team, <>.  Please send any bug reports
       or comments to these addresses.


       getfattr(1), setfattr(1), open(2), stat(2),  getxattr(2),  setxattr(2),
       removexattr(2), and attr(5).