code: def link(src, dst):
      """Hard links ``src`` to ``dst``, returning 0 or errno.
  
      Note that the special errno ``ENOLINK`` will be returned if ``os.link`` isn't
      supported by the operating system.
      """
  
      if not hasattr(os, "link"):
          return ENOLINK
      link_errno = 0
      try:
          os.link(src, dst)
      except OSError as e:
          link_errno = e.errno
      return link_errno
  
imports: import os
  import sys
  import errno
  import shutil
  import random
  import glob
  from warnings import warn
  from hashlib import md5
  from IPython.utils.process import system
  from IPython.utils import py3compat
  from IPython.utils.decorators import undoc
label_desc: Use image node_id 21 for calling a global function with example usage: link(src, dst) and returns: link_errno, ENOLINK