while (readline into $line)
  if $line starts with 'priority'
    print $line if 'priority not already seen'
    remember that priority was seen
  end
  else if $line is blank
    forget that priority was  seen
  end
  else
    print $line
  end
end

##</code><code>##

while (readline into $line)
  if $line starts with 'priority'
    replace 'priority' with 'bandwidth' if 'priority already seen'
    remember that priority was seen
  end
  else if $line is blank
    forget that priority was  seen
  end
  print $line
end