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).