g77 program for converting unformatted files

[Bud Davis]

hello all,

in case anyone is interested, below is a g77 program
that will convert a g77 unformatted file to one that
is readable by gfortran.

there has been a lot of e-mail traffic about these
issues; here is a code snippet that might ease the
problems for some users.  i know how easy it is to say
"just write a little program to do it" and also how
difficult actually realizing a piece of code can be. 
many fortran users are engineers and scientists who
want to solve equations, not play with bytes.


the code is not pretty and has only been tested on a
handful of examples, but it should be enough to get
someone started.  changing the code to go in the other
direction should be very straightforward. 

provided 'as is, where is' with no warranty of any
kind !!


--bud davis

! this g77 program converts g77 style 4 byte record
marker files into
! 8 byte record marker files for gfortran.
      implicit none
      integer*4 recm4
      character*1 recm4_char(4)
      equivalence (recm4,recm4_char)
      integer*8 recm8
      character*1 recm8_char(8)
      equivalence (recm8,recm8_char)
      character*1 c
      integer status_in,status_out,i,j
      data status_in / 0 /
      data status_out / 0 /
! unit 7 is the IN FILE
! unit 8 is the OUT FILE
      open(7,file='fort.7',form='unformatted')
      open(8,file='outfile',form='unformatted')
      do while (status_in.ge.0)
! read in the starting marker
          recm4 = 0
          DO J = 1,4
            CALL FGETC(7,recm4_char(J),status_in)
            IF (status_in.eq.-1) goto 100
          END DO
          recm8 = recm4
          DO J = 1, 8
            CALL FPUTC(8,recm8_char(J),status_out)
          END DO
          DO  I = 1,RECM4
              CALL FGETC(7,C,status_in)
              CALL FPUTC(8,C,status_out)
          END DO
          DO J = 1,4
            CALL FGETC(7,recm4_char(J),status_in)
          END DO
          DO J = 1, 8
            CALL FPUTC(8,recm8_char(J),status_out)
          END DO
      end do
! EOF detected
 100  continue
      end