editing a binary file

[Anton Shterenlikht]

On Fri, Dec 18, 2009 at 02:09:58AM +0100, Rolf Nielsen wrote:
> Anton Shterenlikht wrote:
> > I'm creating binary files in fortran.
> > Fortran adds 4 byte record delimiters at the beginning
> > and the end of each record, which, in the case of a binary
> > file, is just at the beginning and at the end of the file.
> > I need to delete these record delimiters, because the
> > software I use to visualise the binary files interprets
> > them as data. But I don't know how. I've looked at
> > hexdump and od, but those are only dumping (I think)
> > file contents, and I cannot see how to edit a file with them.
> > 
> > Any advice?
> > 
> > many thanks
> > anton
> > 
> 
> Hello Anton,
> 
> My bet would be /usr/ports/editors/hexedit. Been a while since I've used 
> it, but AFAIR, it has a curses or a curses like interface, and it's 
> fairly simple to use, yet sufficiently powerful for most normal binary 
> editing. If you want a GUI, I believe gnome (and probably KDE as well) 
> has its own hex editor.

thank you. hexedit does the job on small files, but is quite
clunky. If I've a xGB file and I need to delete the first and
the last record, this becomes quite hard, if at all possible.

I didn't appreciate it's not that simple.

Perhaps I can read a file with C and write back? I can't
remember if C supports binary files, and whether it
also writes some record delimiters.

many thanks
anton

-- 
Anton Shterenlikht
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