editing a binary file

[Greg Larkin]

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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.
> 
> -Warren Block * Rapid City, South Dakota USA

This should do it:

dd if=oldfile of=newfile bs=1 skip=4

Hope that helps,
Greg
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Greg Larkin

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