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).