setxattr

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



NAME
       setxattr, lsetxattr, fsetxattr - set an extended attribute value

SYNOPSIS
       #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 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.

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 remaining
              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
              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.

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

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), symlink(7), xattr(7)

COLOPHON
       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
       https://www.kernel.org/doc/man-pages/.



Linux                              2021-03-22                        SETXATTR(2)