subroutine file_name_inc ( file_name )

!*****************************************************************************80
!
!! FILE_NAME_INC increments a partially numeric filename.
!
!  Discussion:
!
!    It is assumed that the digits in the name, whether scattered or
!    connected, represent a number that is to be increased by 1 on
!    each call.  If this number is all 9's on input, the output number
!    is all 0's.  Non-numeric letters of the name are unaffected.
!
!    If the name is empty, then the routine stops.
!
!    If the name contains no digits, the empty string is returned.
!
!  Example:
!
!      Input            Output
!      -----            ------
!      'a7to11.txt'     'a7to12.txt'
!      'a7to99.txt'     'a8to00.txt'
!      'a9to99.txt'     'a0to00.txt'
!      'cat.txt'        ' '
!      ' '              STOP!
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    14 September 2005
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    Input/output, character ( len = * ) FILE_NAME.
!    On input, a character string to be incremented.
!    On output, the incremented string.
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  character c
  integer change
  integer digit
  character ( len = * ) file_name
  integer i
  integer lens

  lens = len_trim ( file_name )

  if ( lens <= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'FILE_NAME_INC - Fatal error!'
    write ( *, '(a)' ) '  The input string is empty.'
    stop
  end if

  change = 0

  do i = lens, 1, -1

    c = file_name(i:i)

    if ( lge ( c, '0' ) .and. lle ( c, '9' ) ) then

      change = change + 1

      digit = ichar ( c ) - 48
      digit = digit + 1

      if ( digit == 10 ) then
        digit = 0
      end if

      c = char ( digit + 48 )

      file_name(i:i) = c

      if ( c /= '0' ) then
        return
      end if

    end if

  end do
!
!  No digits were found.  Return blank.
!
  if ( change == 0 ) then
    file_name = ' '
    return
  end if

  return
end
subroutine timestamp ( )

!*****************************************************************************80
!
!! TIMESTAMP prints the current YMDHMS date as a time stamp.
!
!  Example:
!
!    31 May 2001   9:45:54.872 AM
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    18 May 2013
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    None
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  character ( len = 8 ) ampm
  integer d
  integer h
  integer m
  integer mm
  character ( len = 9 ), parameter, dimension(12) :: month = (/ &
    'January  ', 'February ', 'March    ', 'April    ', &
    'May      ', 'June     ', 'July     ', 'August   ', &
    'September', 'October  ', 'November ', 'December ' /)
  integer n
  integer s
  integer values(8)
  integer y

  call date_and_time ( values = values )

  y = values(1)
  m = values(2)
  d = values(3)
  h = values(5)
  n = values(6)
  s = values(7)
  mm = values(8)

  if ( h < 12 ) then
    ampm = 'AM'
  else if ( h == 12 ) then
    if ( n == 0 .and. s == 0 ) then
      ampm = 'Noon'
    else
      ampm = 'PM'
    end if
  else
    h = h - 12
    if ( h < 12 ) then
      ampm = 'PM'
    else if ( h == 12 ) then
      if ( n == 0 .and. s == 0 ) then
        ampm = 'Midnight'
      else
        ampm = 'AM'
      end if
    end if
  end if

  write ( *, '(i2,1x,a,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) &
    d, trim ( month(m) ), y, h, ':', n, ':', s, '.', mm, trim ( ampm )

  return
end