setxattr

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 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 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.

       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 5.03 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                             2019-08-02                       SETXATTR(2)