SETXATTR(2) Linux Programmer's Manual SETXATTR(2)
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 attr(5).
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.
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,
In addition, the errors documented in stat(2) can also occur.
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), attr(5), symlink(7)
Linux 2015-02-21 SETXATTR(2)