SETXATTR
Section: Linux Programmer's Manual (2)
Updated: 2019-08-02
Page Index
NAME
setxattr, lsetxattr, fsetxattr - set an extended attribute value
SYNOPSIS
#include <sys/types.h>
#include <sys/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 fd, const char *name,
const void *value, size_t size, int flags);
DESCRIPTION
Extended attributes are
name:
value
pairs associated with inodes (files, directories, symbolic links, 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
xattr(7).
setxattr()
sets the
value
of the extended attribute identified by
name
and associated with the given
path
in the filesystem.
The
size
argument specifies the size (in bytes) of
value;
a zero-length value is permitted.
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 referred to by
fd
(as returned by
open(2))
in place of
path.
An extended attribute name is a 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.
By default
(i.e.,
flags
is zero),
the extended attribute will be created if it does not exist,
or the value will be replaced if the attribute already exists.
To modify these semantics, one of the following values can be specified in
flags:
- XATTR_CREATE
-
Perform a pure create, which fails if the named attribute exists already.
- XATTR_REPLACE
-
Perform a pure replace operation,
which fails if the named attribute does not already exist.
RETURN VALUE
On success, zero is returned.
On failure, -1 is returned and
errno
is set appropriately.
ERRORS
- EDQUOT
-
Disk quota limits meant that
there is insufficient space remaining to store the extended attribute.
- EEXIST
-
XATTR_CREATE
was specified, and the attribute exists already.
- ENODATA
-
XATTR_REPLACE
was specified, and the attribute does not exist.
- ENOSPC
-
There is insufficient space remaining to store the extended attribute.
- ENOTSUP
-
The namespace prefix of
name
is not valid.
- ENOTSUP
-
Extended attributes are not supported by the filesystem, or are disabled,
- EPERM
-
The file is marked immutable or append-only.
(See
ioctl_iflags(2).)
In addition, the errors documented in
stat(2)
can also occur.
- ERANGE
-
The size of
name
or
value
exceeds a filesystem-specific limit.
VERSIONS
These system calls have been available on Linux since kernel 2.4;
glibc support is provided since version 2.3.
CONFORMING TO
These system calls are Linux-specific.
SEE ALSO
getfattr(1),
setfattr(1),
getxattr(2),
listxattr(2),
open(2),
removexattr(2),
stat(2),
symlink(7),
xattr(7)
COLOPHON
This page is part of release 5.10 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.