[Python-Dev] Identifying magic prefix on Python files?

[Eric S. Raymond]

Tim Peters <tim.one@home.com>:
> [Eric S. Raymond]
> > Python's .pyc files don't have a magic prefix that the file(1)
> > utility can recognize.
> 
> Well, they *do* (#define MAGIC in import.c), but it changes from time to
> time.  Here's a NEWS item from 2.1a1:
> 
>     - The interpreter accepts now bytecode files on the command
>       line even if they do not have a .pyc or .pyo extension. On
>       Linux, after executing
> 
>       echo ':pyc:M::\x87\xc6\x0d\x0a::/usr/local/bin/python:' >
>          /proc/sys/fs/binfmt_misc/register
> 
>       any byte code file can be used as an executable (i.e. as an
>       argument to execve(2)).
> 
> However, the magic number has changed twice since then (in import.c rev
> 2.157 and again in rev 2.160), so the NEWS item is two changes obsolete.
> The current magic number can be obtained (as a 4-bytes string) via
> 
> import imp
> MAGIC = imp.get_magic()

Interesting.  I presume this has to be repeated at every boot?
 
> Note too that the method used for encoding the date runs out of bits at the
> end of 2001, so the current scheme is on its last legs regardless.

So this has to be fixed anyway.  I'm sure we can come up with a better 
scheme, perhaps one modeled after the PNG header.
-- 
		<a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a>

Are we at last brought to such a humiliating and debasing degradation,
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