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 argu-
ment specifies the size (in bytes) of value; a zero-length value is
permitted.
lsetxattr() is identical to setxattr(), except in the case of a sym-
bolic 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
associated with an individual inode. The value of an extended at-
tribute is a chunk of arbitrary textual or binary data of specified
length.
By default (i.e., flags is zero), the extended attribute will be cre-
ated if it does not exist, or the value will be replaced if the at-
tribute already exists. To modify these semantics, one of the follow-
ing 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
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.
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 6.7 2023-10-31 setxattr(2)
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