NAME

       getxattr, lgetxattr, fgetxattr - retrieve an extended attribute value

SYNOPSIS

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

       ssize_t getxattr (const char *path, const char *name,
                            void *value, size_t size);
       ssize_t lgetxattr (const char *path, const char *name,
                            void *value, size_t size);
       ssize_t fgetxattr (int filedes, const char *name,
                            void *value, size_t size);

DESCRIPTION

       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).

       getxattr retrieves the value of the extended attribute identified by name  and  associated
       with the given path in the filesystem.  The length of the attribute value is returned.

       lgetxattr  is identical to getxattr, except in the case of a symbolic link, where the link
       itself is interrogated, not the file that it refers to.

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

       An  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.   The value of an extended attribute is a chunk of arbitrary textual or binary data
       of specified length.

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

       The interface is designed to allow guessing  of  initial  buffer  sizes,  and  to  enlarge
       buffers when the return value indicates that the buffer provided was too small.

RETURN VALUE

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

       If the named attribute does not exist, or the process has no  access  to  this  attribute,
       errno is set to ENOATTR.

       If the size of the value 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 here.

AUTHORS

       Andreas Gruenbacher, <a.gruenbacher@bestbits.at> and the SGI XFS development team, <linux-
       xfs@oss.sgi.com>.  Please send any bug reports or comments to these addresses.

SEE ALSO

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