setxattr

SETXATTR(2)			 System calls			  SETXATTR(2)



NAME
       setxattr, lsetxattr, fsetxattr - set an extended attribute value

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

       int setxattr (const char *path, const char *name,
		       const void *value, size_t size, int flags);
       int lsetxattr (const char *path, const char *name,
		       const void *value, size_t size, int flags);
       int fsetxattr (int filedes, const char *name,
		       const void *value, size_t size, int flags);

DESCRIPTION
       Extended	 attributes  are  name:value  pairs  associated	 with  inodes
       (files, directories, symlinks, etc).  They are extensions to the	 nor-
       mal  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).

       setxattr	 sets  the value of the extended attribute identified by name
       and associated with the given path in the filesystem.  The size of the
       value must be specified.

       lsetxattr  is  identical to setxattr, except in the case of a symbolic
       link, where the extended attribute is set on the link itself, not  the
       file that it refers to.

       fsetxattr is identical to setxattr, only the extended attribute is set
       on the open file pointed to by filedes (as  returned  by	 open(2))  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.

       The  flags parameter can be used to refine the semantics of the opera-
       tion.  XATTR_CREATE specifies a pure create, which fails if the	named
       attribute  exists  already.   XATTR_REPLACE  specifies  a pure replace
       operation, which fails if the named attribute does not already  exist.
       By  default (no flags), the extended attribute will be created if need
       be, or will simply replace the value if the attribute exists.

RETURN VALUE
       On success, zero is returned.  On failure, -1 is returned and errno is
       set appropriately.

       If  XATTR_CREATE is specified, and the attribute exists already, errno
       is set to EEXIST.  If XATTR_REPLACE is specified,  and  the  attribute
       does not exist, errno is set to ENOATTR.

       If  there  is  insufficient  space  remaining  to  store	 the extended
       attribute, errno is set to either ENOSPC, or EDQUOT if quota  enforce-
       ment was the cause.

       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@computer.org>  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), getxattr(2), listxattr(2),
       removexattr(2), and attr(5).



Dec 2001		     Extended Attributes		  SETXATTR(2)