Either INOUT or OUTPUT

##</code><code>##

  /
    # either this
    ^ S \s+ [-]* \d+ [\.\d+]* \s+ [-]* \d+ [\.\d+]* \s* \( \s* IOPUT
  |
    # or this
    OUTPUT \s* \)
  /ix

##</code><code>##

  /
    # all of this
    ^ S \s+ [-]* \d+ [\.\d+]* \s+ [-]* \d+ [\.\d+]* \s* \( \s*
    # and one of these two
    (?: IOPUT | OUTPUT )
    # and all of this
    \s* \)
  /ix