import os
import ctypes
import ctypes.util
import posix
import pprint

def dump():
    print("--")
    os.system("env")
    print("--")
    with open("/proc/self/environ", "rb") as f:
        env = f.read().split(b"\0")
        pprint.pprint(env)
    print("==")
    print()

filename = ctypes.util.find_library('c')
libc = ctypes.cdll.LoadLibrary(filename)
_getenv = libc.getenv
_getenv.restype = ctypes.c_char_p
_getenv.arg_types = (ctypes.c_char_p,)

def getenv(key):
    key = os.fsencode(key)
    value = _getenv(key)
    if value is not None:
        value = os.fsdecode(value)
    return value

print("[ Start ]")
print(os.environ)
dump()

print("[ Set VAR=VALUE1 ]")
os.environ['VAR'] = 'VALUE1'
print("get -> %s" % getenv('VAR'))
dump()

print("[ Set <empty>=VALUE2 ]")
os.environ[''] = 'VALUE2'
print("get -> %s" % getenv(''))
dump()