attr_getf

ATTR_GET(3)		    XFS Compatibility API		  ATTR_GET(3)



NAME
       attr_get,  attr_getf - get the value of a user attribute of a filesys-
       tem object

C SYNOPSIS
       #include <attr/attributes.h>

       int attr_get (const char *path, const char *attrname,
		     char *attrvalue, int *valuelength, int flags);

       int attr_getf (int fd, const char *attrname,
		      char *attrvalue, int *valuelength, int flags);

DESCRIPTION
       The attr_get and attr_getf functions provide a  way  to	retrieve  the
       value of an attribute.

       Path  points  to a path name for a filesystem object, and fd refers to
       the file descriptor associated with a file.  If the attribute attrname
       exists, the value associated with it will be copied into the attrvalue
       buffer.	The valuelength argument is an input/output argument that  on
       the  call  to  attr_get	should	contain the maximum size of attribute
       value the process is willing to accept.	On  return,  the  valuelength
       will have been modified to show the actual size of the attribute value
       returned.  The flags argument can contain the following	symbols	 bit-
       wise OR´ed together:

       ATTR_ROOT
	      Look  for	 attrname  in the root address space, not in the user
	      address space.  (limited to use by super-user only)

       ATTR_DONTFOLLOW
	      Do not follow symbolic  links  when  resolving  a	 path  on  an
	      attr_get	function  call.	  The  default	is to follow symbolic
	      links.

       attr_get will fail if one or more of the following are true:

       [ENOATTR]	The attribute name given is not associated  with  the
			indicated filesystem object.

       [E2BIG]		The  value of the given attribute is too large to fit
			into the buffer.  The integer  that  the  valuelength
			argument  points  to  has  been	 modified to show the
			actual number of bytes	that  would  be	 required  to
			store the value of that attribute.

       [ENOENT]		The named file does not exist.

       [EPERM]		The effective user ID does not match the owner of the
			file and the effective user ID is not super-user.

       [ENOTDIR]	A component of the path prefix is not a directory.

       [EACCES]		Search permission is denied on	a  component  of  the
			path prefix.

       [EINVAL]		A  bit	was  set  in  the  flag	 argument that is not
			defined for this system call.

       [EFAULT]		Path, attrname, attrvalue, or valuelength points out-
			side the allocated address space of the process.

       [ELOOP]		A  path name lookup involved too many symbolic links.

       [ENAMETOOLONG]	The length of path exceeds {MAXPATHLEN}, or  a	path-
			name component is longer than {MAXNAMELEN}.

       attr_getf will fail if:

       [ENOATTR]      The  attribute  name  given  is not associated with the
		      indicated filesystem object.

       [E2BIG]	      The value of the given attribute is too  large  to  fit
		      into  the	 buffer.   The	integer	 that the valuelength
		      argument points to has been modified to show the actual
		      numnber  of  bytes  that would be required to store the
		      value of that attribute.

       [EINVAL]	      A bit was set in the flag argument that is not  defined
		      for  this	 system call, or fd refers to a socket, not a
		      file.

       [EFAULT]	      Attrname, attrvalue, or valuelength points outside  the
		      allocated address space of the process.

       [EBADF]	      Fd does not refer to a valid descriptor.

DIAGNOSTICS
       On  success, zero is returned.  On error, -1 is returned, and errno is
       set appropriately.

SEE ALSO
       attr(1), attr_multi(3), attr_remove(3), and attr_set(3).



Dec 2001		     Extended Attributes		  ATTR_GET(3)