subroutine parfile_read(par_file,ierr)
c
c      Subroutine that reads in the processing information from the 
c      specified input parameter files. The information is stored in
c      a common block.
c      originally written by Fortunat Kind
c      modified by a.tento 06/03
c
        implicit none
        character*200 par_file
        integer ierr
c
        character*200 line, key, remainder
        integer nunit, i 
        include 'parameters.h'
c
c
        call glun(nunit,ierr)
        if (ierr .ne. 0) goto 40
        open(unit=nunit,file=par_file,status='old')
c
        ierr=0
        do 1 i = 1, 987654321
         read(nunit,'(a80)',end=20) line
         if ( line(1:22) .eq. '### section processing' ) goto 2
1       continue
2       continue
C     jump all comment and empty lines, but display the relevant parts,
C     until the end of the processing section
        do 3 i = 1, 987654321
         read(nunit,'(a200)',end=30) line
         if ( line(1:18) .eq. '### end processing' ) goto 4
                if ((line .ne. '') .and. (line(1:1) .ne. '#')) then
                        call strtok(line,key,remainder,':')
                        if (key .eq. 'freq_spacing') then
                                freq_spacing=remainder
                        else if (key .eq. 'offset_rem') then
                                offset_rem=remainder
                        else if (key .eq. 'taper') then
                                taper=remainder
                        else if (key .eq. 'instrument_resp') then
                                instrument_resp=remainder
                                write(*,400)key
                                ierr = 2
                        else if (key .eq. 'smooth') then
                                smooth=remainder
                        else if (key .eq. 'merge_type') then
                                merge_type=remainder
                        else if (key .eq. 'single_component') then
                                single_component=remainder
                                write(*,400)key
                                ierr = 2
                        else if (key .eq. 'average_type') then
                                average_type=remainder
                                write(*,400)key
                                ierr = 2
                        else if (key .eq. 'average_spectra_out') then
                                average_spectra_out=remainder
                        else if (key .eq. 'single_win_out') then
                                single_win_out=remainder
                        else if (key .eq. 'filter_out') then
                                filter_out=remainder
                        else
c................... undefined key was used, returning error or Warning
                                ierr=1
                        write(*,300)key,par_file
                        return
                        end if
                end if
3       continue
c
4       close(nunit)
        return
c
c
20      write (*,*) ' ERROR in parfile_read:'
        write (*,*) ' line ''### section processing'' not found in file'
        write(*,100)par_file
        ierr=1
        return

30      write (*,*)' WARNING in parfile_read:'
        write (*,*)' following file ended before ''### end processing'''
        write(*,100)par_file
        close(nunit)
        ierr=2
        return

40      write (*,*) ' ERROR in parfile_read:'
        write (*,*) '  could not find free unit number for parameter',
     #                  ' file'
        ierr=1
        return
c
300     format(' ERROR : undefined parameter key : ''',a32,
     #         ''' in file :',/,1x,a200)
100     format(1x,a200)
400     format(' WARNING: parameter ''',a,''' obsolete:',
     #         ' not taken into account')
c
        end