old_contents: import re
  from subprocess import Popen, PIPE
  from thefuck.utils import memoize
  from thefuck.shells import shell
  
  patterns = [r"bind on address \('.*', (?P<port>\d+)\)",
              r'Unable to bind [^ ]*:(?P<port>\d+)',
              r"can't listen on port (?P<port>\d+)",
              r'listen EADDRINUSE [^ ]*:(?P<port>\d+)']
  
  
  @memoize
  def _get_pid_by_port(port):
      proc = Popen(['lsof', '-i', ':{}'.format(port)], stdout=PIPE)
      lines = proc.stdout.read().decode().split('\n')
      if len(lines) > 1:
          return lines[1].split()[1]
      else:
          return None
  
  
  @memoize
  def _get_used_port(command):
      for pattern in patterns:
          matched = (re.search(pattern, command.stderr)
                     or re.search(pattern, command.stdout))
          if matched:
              return matched.group('port')
  
  
  def match(command):
      port = _get_used_port(command)
      return port and _get_pid_by_port(port)
  
  
  def get_new_command(command):
      port = _get_used_port(command)
      pid = _get_pid_by_port(port)
      return shell.and_(u'kill {}'.format(pid), command.script)
  
new_contents: import re
  from subprocess import Popen, PIPE
  from thefuck.utils import memoize, which
  from thefuck.shells import shell
  
  enabled_by_default = bool(which('lsof'))
  
  patterns = [r"bind on address \('.*', (?P<port>\d+)\)",
              r'Unable to bind [^ ]*:(?P<port>\d+)',
              r"can't listen on port (?P<port>\d+)",
              r'listen EADDRINUSE [^ ]*:(?P<port>\d+)']
  
  
  @memoize
  def _get_pid_by_port(port):
      proc = Popen(['lsof', '-i', ':{}'.format(port)], stdout=PIPE)
      lines = proc.stdout.read().decode().split('\n')
      if len(lines) > 1:
          return lines[1].split()[1]
      else:
          return None
  
  
  @memoize
  def _get_used_port(command):
      for pattern in patterns:
          matched = (re.search(pattern, command.stderr)
                     or re.search(pattern, command.stdout))
          if matched:
              return matched.group('port')
  
  
  def match(command):
      port = _get_used_port(command)
      return port and _get_pid_by_port(port)
  
  
  def get_new_command(command):
      port = _get_used_port(command)
      pid = _get_pid_by_port(port)
      return shell.and_(u'kill {}'.format(pid), command.script)
  
subject: Disable `port_already_in_use` on systems without `lsof`