#! /bin/csh -f
#
#  set $status = 1 (true) if year string yy is valid
#  set $status = 0 (false) otherwise
#
#
  set silent = FALSE
  if ( $#argv == 2 ) then
    if ( "$argv[2]" == "silent" ) then
      set silent = TRUE
    else
      echo "yy_valid:  invalid 2nd argument keyword:  $argv[2]"
      exit 0
    endif
  else if ( $#argv != 1 ) then
    echo "yy_valid:  wrong number of arguments ($#argv)."
    exit 0
  endif
#
  set string = "$argv[1]"
  switch ($string)
    case [0-9][0-9]:
      exit 1
      breaksw
    default:
      if ( $silent == FALSE ) then
        echo "yy_valid:  invalid yy string:  $string"
      endif
      exit 0
      breaksw
  endsw
