! Copyright 2005-2007 ECMWF
! 
! Licensed under the GNU Lesser General Public License which
! incorporates the terms and conditions of version 3 of the GNU
! General Public License.
! See LICENSE and gpl-3.0.txt for details.
!
!
!  Description: how to copy a message in memory
!
!
!  Author: Anne Fouilloux
!
!
program copy
  use grib_api
  implicit none
  integer                            :: err, centre
  integer(kind=kindOfSize)           :: byte_size
  integer                            :: infile,outfile
  integer                            :: igrib_in,iret
  integer                            :: igrib_out
  character(len=1), dimension(:), allocatable :: message

  
  call grib_open_file(infile,'../../data/constant_field.grib1','r')
  call grib_open_file(outfile,'out.grib1','w')

  !     a new grib message is loaded from file
  !     igrib is the grib id to be used in subsequent calls
  call grib_new_from_file(infile,igrib_in)

  call grib_get_message_size(igrib_in, byte_size)
  allocate(message(byte_size), stat=err)

  call grib_copy_message(igrib_in,message)

  call grib_new_from_message(igrib_out, message)

  centre=80
  call grib_set(igrib_out,"centre",centre)

!  write messages to a file
  call grib_write(igrib_out,outfile)

  call grib_release(igrib_out)

  call grib_release(igrib_in)

  call grib_close_file(infile)
  call grib_close_file(outfile)
  deallocate(message)

end program copy