! This software is distributed under the following terms:
! 
! Copyright (C) 2005 Dominik Epple
! 
! Redistribution and use in source and binary forms, with or without
! modification, are permitted provided that the following conditions
! are met:
! 1. Redistributions of source code must retain the above copyright
!    notice, this list of conditions and the following disclaimer.
! 2. Redistributions in binary form must reproduce the above copyright
!    notice, this list of conditions and the following disclaimer in the
!    documentation and/or other materials provided with the distribution.
! 
! THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
! ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
! FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! SUCH DAMAGE.

      module getoptions
        implicit none
        save
        character(len=80) :: optarg
        integer :: optind=1

        ! this variable should be module private - no plan how to do that
        integer :: optstr_ind
        contains
          character function getopt(optstr)
            character(len=*),intent(IN) :: optstr

            integer :: argc
            character(len=80) :: arg
            character :: okey
            integer :: found

            integer :: iargc
            argc=iargc()
            if(optind.gt.argc) then
              getopt='>'
              return
            end if
            call getarg(optind, arg)
            if(arg(1:1).eq.'-') then
              okey=arg(2:2)
              found=0
              optstr_ind=1
              do while(optstr_ind.le.len(optstr))
                if(optstr(optstr_ind:optstr_ind).eq.okey) then
                  found=1
                  if(optstr(optstr_ind+1:optstr_ind+1).eq.':') then
                    optstr_ind=optstr_ind+1
                    optind=optind+1
                    call getarg(optind, optarg)
                  end if
                  exit
                end if
                optstr_ind=optstr_ind+1
              end do
              if(found.gt.0) then
                getopt=okey
              else
                getopt='!'
                optarg=arg
              end if
            else
              getopt='.'
              optarg=arg
            end if
            optind=optind+1
            return
          end function
      end module