FUNCTION strpad, input_string, total_length, CLIP=clip
; Pad a string out to the size total_length
; If CLIP keyword is present then clip to the size as well,
; default is to give all chars if it is too long.
in_len = STRLEN(input_string)
if in_len GE total_length then begin
  ; string is already long enough (keep extra too)
  padded = input_string
  ; clip it to length if desired
  if KEYWORD_SET(CLIP) then begin
    padded = STRMID(padded,0,total_length)
  end
end else begin
  padded = input_string
  for ip = 1, total_length - in_len  do padded = padded + ' '
end

RETURN, padded
END