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  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).

   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
   operation.  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
   enforcement 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@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), getxattr(2), listxattr(2),
   removexattr(2), and attr(5).

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