Passing argument containg nullbyte (\x00) to subprocess.call

Question

#!/usr/bin/env python
from subprocess import call

try:
    call(['echo', "aabbccddee".decode('hex')])
    print 'Input without \\x00 works!'
except Exception as e:
    print 'Input without \\x00 throws exception: ' + str(e)

try:
    call(['echo', "aabbccdd00ee".decode('hex')]) # The input contains \x00
    print 'Input with \\x00 works!'
except Exception as e:
    print 'Input with \\x00 throws exception: ' + str(e)

Returns the following (tested with Python 2.7 on RHEL 6):

▒▒▒▒▒
Input without \x00 works!
Input with \x00 throws exception: execv() arg 2 must contain only strings

Questions:

• Is this expected behavior by subprocess.call or might this be a bug?
• Is there any way I can pass binary data (directly) containing \x00 to another executable within a python script? It will probably work using shell=True, but I would prefer another way, if there is any.

Note:

• >>> type("00".decode('hex')) <type 'str'>

• Running echo $'\x00' directly works as expected.

EDIT

This seems to be correct behavior after more research. Due to the execve(2) semantics it is not possible to pass a string containing a null byte as argument.

See:

• $ echo $'\x55\x55\x55\x00\x55\x55' UUU

However, I couldn't really find anymore info on this (second question especially, as it seems shell=True won't help either (all data after the null byte wouldn't be passed)). I leave this question open for a while, maybe someone can provide a deeper insight or share some useful resources on this.