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Re: Extra bytes in OSX vs classic binaries

Joe:

I tried the direct access method and it works fine (naturally, the byte-by-byte method suggested immediately below is comparatively slow for large files, if that is an issue). I found the "direct access" solution (also offered by Drew and Eric; a pox on Digest Mode! :) by Googling after getting a heads up on the basic problem from Jeff Jonas and Roy Mendelssohn. Here is Clive Page's take on the issue, found at

http://www.dbforums.com/archive/index.php/t-951804.html:

====================================
In article <bn0rpr$dcr$email@hidden>,
Rob McDonald <email@hidden> wrote:
Is there any way to get g77 to read/write files opened with the "
form='binary' " flag? If not, and if there are any g77 developers
listening, is there any chance that this capability will be added?

What you may be able to do (sorry if anyone else has already suggested this) is to open
the file ACCESS='DIRECT', FORM='FORMATTED', RECL=1

This means each character in the file turns into one record. You can then do a formatted
direct access read into a character array and get individual bytes, something like this:

CHARACTER MYARRAY(somesize)
READ(UNIT=myunit, FMT='(A)', REC=nrec) (MYARRAY(I),I=1,something)

The rules for formatted direct access say that you read from sucessive records when you
run out of items in the current record, so you don't need one READ statement per byte.

--
Clive Page
====================================


Many thanks to all who contributed to this thread,

Richard Hartman


From: Joe Koski <email@hidden>

on 6/25/04 3:55 PM, Drew McCormack at email@hidden wrote:


On Jun 25, 2004, at 5:47 PM, Joe Koski wrote:

Please excuse me for piggy-backing, but I have a similar issue for
which
list members may know the answer.

I have a Fortran 77 code that I compile with g77-3.5. The program can
write
binary output files for reading by a post-processor (GMV). The
post-processor is C code, probably compiled with gcc. Apparently the
g77
binary file format differs from the gcc binary file format as
described in
this thread. As a result the C language post-processor can't read the
g77
binary output, and I'm forced to use ASCII instead. As far as I know,
the
post-processor won't read .hdf files, either.

My question: are there compiler switches for g77 that will allow the
g77
binary output files to be compatible with gcc, similar to the -N3
Absoft
option described below? Any tricks? How about running the particular
g77
output routine through f2c and then compiling it with gcc?

One option is to write the data to a fortran direct access file, with a
record length of 1. This is basically the same as writing in C. No
extra record information will appear in the file, only the data you
write.

Drew

Nice trick! If it works, I owe you the network equivalent of a beer. I'll
give it a try and report back to the list.

Joe Koski
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