editing a binary file

[Anton Shterenlikht]

On Thu, Dec 17, 2009 at 06:38:04PM -0700, Warren Block wrote:
> On Fri, 18 Dec 2009, 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.
> 
> truncate -4 myfile should get rid of the last four bytes.  Maybe there's 
> a similar efficient way to truncate the start of a file.

thank you, that works fine:

> hexdump -C fort.10
00000000  01 00 00 00 01 01 00 00  00                       |.........|
00000009

> truncate -s -4 fort.10 

> hexdump -C fort.10
00000000  01 00 00 00 01                                    |.....|
00000005
> 

-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
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