setxattr(2) System Calls Manual setxattr(2)
NAME
setxattr, lsetxattr, fsetxattr - set an extended attribute value
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#include <sys/xattr.h>
int setxattr(const char *path, const char *name,
const void value[.size], size_t size, int flags);
int lsetxattr(const char *path, const char *name,
const void value[.size], size_t size, int flags);
int fsetxattr(int fd, const char *name,
const void value[.size], 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 permit-
ted.
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 in-
cludes a namespace prefix; there may be several, disjoint namespaces as-
sociated 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 al-
ready 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 at-
tribute does not already exist.
RETURN VALUE
On success, zero is returned. On failure, -1 is returned and errno is
set to indicate the error.
ERRORS
EDQUOT Disk quota limits meant that there is insufficient space remain-
ing 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 at-
tribute.
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 FS_IOC_SET-
FLAGS(2const).)
In addition, the errors documented in stat(2) can also occur.
ERANGE The size of name or value exceeds a filesystem-specific limit.
STANDARDS
Linux.
HISTORY
Linux 2.4, glibc 2.3.
SEE ALSO
getfattr(1), setfattr(1), getxattr(2), listxattr(2), open(2), removex-
attr(2), stat(2), symlink(7), xattr(7)
Linux man-pages 6.9.1 2024-06-13 setxattr(2)
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