Change column in binary file to check contents; Write binary

[txwaiting4u]

I have a binary file that I am splitting based on a particular field in the file; it's a one character field. The field in ascii (text) would be a 1 or a 2. However, I can't check for a 1 or a 2 because it is in binary. How do I check for a 1 or 2 yet write out the output files in binary?

I tried dd to convert the file to ascii first but that didn't work. I would prefer to check the field by converting it to ascii in a variable which wouldn't modify the file at all. Anyone know of a possible solution? Thanks!

 

[Annihilannic]

This seems to work:

awk '
        BEGIN { RS=ORS=1 }
        {
                filename=sprintf("file.%05d",++n)
                print > filename
        }
' inputfilename

Note that this will put a record separater at the end of every file though. You could change ORS to "" if you don't want that.

Annihilannic.