|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | SEE ALSO | COLOPHON |
|
SETXATTR(2) Linux Programmer's Manual SETXATTR(2)
setxattr, lsetxattr, fsetxattr - set an extended attribute value
#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);
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.
On success, zero is returned. On failure, -1 is returned and errno
is set appropriately.
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.
ENOATTR
XATTR_REPLACE was specified, and the attribute does not exist.
(ENOATTR is defined to be a synonym for ENODATA in
<attr/xattr.h>.)
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.
These system calls have been available on Linux since kernel 2.4;
glibc support is provided since version 2.3.
These system calls are Linux-specific.
getfattr(1), setfattr(1), getxattr(2), listxattr(2), open(2),
removexattr(2), stat(2), symlink(7), xattr(7)
This page is part of release 4.15 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/.
Linux 2017-03-13 SETXATTR(2)
Pages that refer to this page: getxattr(2), listxattr(2), open(2), removexattr(2), syscalls(2), capabilities(7), inotify(7), symlink(7), xattr(7)
Copyright and license for this manual page
|
HTML rendering created 2018-02-02 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.
|
|