setxattr(2) — Linux manual page


SETXATTR(2)             Linux Programmer's Manual            SETXATTR(2)

NAME         top

       setxattr, lsetxattr, fsetxattr - set an extended attribute value

SYNOPSIS         top

       #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         top

       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:

              Perform a pure create, which fails if the named attribute
              exists already.

              Perform a pure replace operation, which fails if the named
              attribute does not already exist.

RETURN VALUE         top

       On success, zero is returned.  On failure, -1 is returned and
       errno is set to indicate the error.

ERRORS         top

       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

              XATTR_REPLACE was specified, and the attribute does not

       ENOSPC There is insufficient space remaining to store the
              extended attribute.

              The namespace prefix of name is not valid.

              Extended attributes are not supported by the filesystem,
              or are disabled,

       EPERM  The file is marked immutable or append-only.  (See

       In addition, the errors documented in stat(2) can also occur.

       ERANGE The size of name or value exceeds a filesystem-specific

VERSIONS         top

       These system calls have been available on Linux since kernel 2.4;
       glibc support is provided since version 2.3.

CONFORMING TO         top

       These system calls are Linux-specific.

SEE ALSO         top

       getfattr(1), setfattr(1), getxattr(2), listxattr(2), open(2),
       removexattr(2), stat(2), symlink(7), xattr(7)

COLOPHON         top

       This page is part of release 5.13 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

Linux                          2021-03-22                    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)