On Friday, 05/20/2016 at 03:05 GMT, Hendrik Brueckner 
<[email protected]> wrote:
> To recognize the file format the "magic" patterns are used.  See also 
the
> definitions in /usr/share/misc/magic and magic(5) man page.  If you know
> how to detect packed CMS files, you can add the signature there (or for
> testing locally) and check if file is then able to recognize it.

Unfortunately part of the signature is in the LRECL 1024 and RECFM F, but 
those aren't visible to apps.  The only thing you can do in Linux (without 
actually unpacking the file) is
- Check for a file length that's a multiple of 1024
- The first four bytes are 0x000140E5 or 0x000140C6

Alan Altmark

Senior Managing z/VM and Linux Consultant
Lab Services System z Delivery Practice
IBM Systems & Technology Group
ibm.com/systems/services/labservices
office: 607.429.3323
mobile; 607.321.7556
[email protected]
IBM Endicott

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