void
Py_InitializeEx(int install_sigs)
{
    PyInterpreterState *interp;
    PyThreadState *tstate;
    PyObject *bimod, *sysmod;
    char *p;
    char *icodeset = NULL; /* On Windows, input codeset may theoretically
                              differ from output codeset. */
    char *codeset = NULL;
    char *errors = NULL;
    int free_codeset = 0;
    int overridden = 0;
    PyObject *sys_stream;
#if defined(Py_USING_UNICODE) && defined(HAVE_LANGINFO_H) && defined(CODESET)
    char *saved_locale, *loc_codeset;
#endif
#ifdef MS_WINDOWS
    char ibuf[128];
    char buf[128];
#endif
    extern void _Py_ReadyTypes(void);

    if (initialized)
        return;
    initialized = 1;

    if ((p = Py_GETENV("PYTHONDEBUG")) && *p != '\0')
        Py_DebugFlag = add_flag(Py_DebugFlag, p);
    if ((p = Py_GETENV("PYTHONVERBOSE")) && *p != '\0')
        Py_VerboseFlag = add_flag(Py_VerboseFlag, p);
    if ((p = Py_GETENV("PYTHONOPTIMIZE")) && *p != '\0')
        Py_OptimizeFlag = add_flag(Py_OptimizeFlag, p);
    if ((p = Py_GETENV("PYTHONDONTWRITEBYTECODE")) && *p != '\0')
        Py_DontWriteBytecodeFlag = add_flag(Py_DontWriteBytecodeFlag, p);
    /* The variable is only tested for existence here; _PyRandom_Init will
       check its value further. */
    if ((p = Py_GETENV("PYTHONHASHSEED")) && *p != '\0')
        Py_HashRandomizationFlag = add_flag(Py_HashRandomizationFlag, p);

    _PyRandom_Init();

    interp = PyInterpreterState_New();
    if (interp == NULL)
        Py_FatalError("Py_Initialize: can't make first interpreter");

    tstate = PyThreadState_New(interp);
    if (tstate == NULL)
        Py_FatalError("Py_Initialize: can't make first thread");
    (void) PyThreadState_Swap(tstate);

    _Py_ReadyTypes();

    if (!_PyFrame_Init())
        Py_FatalError("Py_Initialize: can't init frames");

    if (!_PyInt_Init())
        Py_FatalError("Py_Initialize: can't init ints");

    if (!_PyLong_Init())
        Py_FatalError("Py_Initialize: can't init longs");

    if (!PyByteArray_Init())
        Py_FatalError("Py_Initialize: can't init bytearray");

    _PyFloat_Init();

    interp->modules = PyDict_New();
    if (interp->modules == NULL)
        Py_FatalError("Py_Initialize: can't make modules dictionary");
    interp->modules_reloading = PyDict_New();
    if (interp->modules_reloading == NULL)
        Py_FatalError("Py_Initialize: can't make modules_reloading dictionary");

#ifdef Py_USING_UNICODE
    /* Init Unicode implementation; relies on the codec registry */
    _PyUnicode_Init();
#endif

    bimod = _PyBuiltin_Init();
    if (bimod == NULL)
        Py_FatalError("Py_Initialize: can't initialize __builtin__");
    interp->builtins = PyModule_GetDict(bimod);
    if (interp->builtins == NULL)
        Py_FatalError("Py_Initialize: can't initialize builtins dict");
    Py_INCREF(interp->builtins);

    sysmod = _PySys_Init();
    if (sysmod == NULL)
        Py_FatalError("Py_Initialize: can't initialize sys");
    interp->sysdict = PyModule_GetDict(sysmod);
    if (interp->sysdict == NULL)
        Py_FatalError("Py_Initialize: can't initialize sys dict");
    Py_INCREF(interp->sysdict);
    _PyImport_FixupExtension("sys", "sys");
    PySys_SetPath(Py_GetPath());
    PyDict_SetItemString(interp->sysdict, "modules",
                         interp->modules);

    _PyImport_Init();

    /* initialize builtin exceptions */
    _PyExc_Init();
    _PyImport_FixupExtension("exceptions", "exceptions");

    /* phase 2 of builtins */
    _PyImport_FixupExtension("__builtin__", "__builtin__");

    _PyImportHooks_Init();

    if (install_sigs)
        initsigs(); /* Signal handling stuff, including initintr() */

    /* Initialize warnings. */
    _PyWarnings_Init();
    if (PySys_HasWarnOptions()) {
        PyObject *warnings_module = PyImport_ImportModule("warnings");
        if (!warnings_module)
            PyErr_Clear();
        Py_XDECREF(warnings_module);
    }

    initmain(); /* Module __main__ */

    /* auto-thread-state API, if available */
#ifdef WITH_THREAD
    _PyGILState_Init(interp, tstate);
#endif /* WITH_THREAD */

    if (!Py_NoSiteFlag)
        initsite(); /* Module site */

    if ((p = Py_GETENV("PYTHONIOENCODING")) && *p != '\0') {
        p = icodeset = codeset = strdup(p);
        free_codeset = 1;
        errors = strchr(p, ':');
        if (errors) {
            *errors = '\0';
            errors++;
        }
        overridden = 1;
    }

#if defined(Py_USING_UNICODE) && defined(HAVE_LANGINFO_H) && defined(CODESET)
    /* On Unix, set the file system encoding according to the
       user's preference, if the CODESET names a well-known
       Python codec, and Py_FileSystemDefaultEncoding isn't
       initialized by other means. Also set the encoding of
       stdin and stdout if these are terminals, unless overridden.  */

    if (!overridden || !Py_FileSystemDefaultEncoding) {
        saved_locale = strdup(setlocale(LC_CTYPE, NULL));
        setlocale(LC_CTYPE, "");
        loc_codeset = nl_langinfo(CODESET);
        if (loc_codeset && *loc_codeset) {
            PyObject *enc = PyCodec_Encoder(loc_codeset);
            if (enc) {
                loc_codeset = strdup(loc_codeset);
                Py_DECREF(enc);
            } else {
                if (PyErr_ExceptionMatches(PyExc_LookupError)) {
                    PyErr_Clear();
                    loc_codeset = NULL;
                } else {
                    PyErr_Print();
                    exit(1);
                }
            }
        } else
            loc_codeset = NULL;
        setlocale(LC_CTYPE, saved_locale);
        free(saved_locale);

        if (!overridden) {
            codeset = icodeset = loc_codeset;
            free_codeset = 1;
        }

        /* Initialize Py_FileSystemDefaultEncoding from
           locale even if PYTHONIOENCODING is set. */
        if (!Py_FileSystemDefaultEncoding) {
            Py_FileSystemDefaultEncoding = loc_codeset;
            if (!overridden)
                free_codeset = 0;
        }
    }
#endif

#ifdef MS_WINDOWS
    if (!overridden) {
        icodeset = ibuf;
        codeset = buf;
        sprintf(ibuf, "cp%d", GetConsoleCP());
        sprintf(buf, "cp%d", GetConsoleOutputCP());
    }
#endif

    if (codeset) {
        sys_stream = PySys_GetObject("stdin");
        if ((overridden || isatty_no_error(sys_stream)) &&
            PyFile_Check(sys_stream)) {
            if (!PyFile_SetEncodingAndErrors(sys_stream, icodeset, errors))
                Py_FatalError("Cannot set codeset of stdin");
        }

        sys_stream = PySys_GetObject("stdout");
        if ((overridden || isatty_no_error(sys_stream)) &&
            PyFile_Check(sys_stream)) {
            if (!PyFile_SetEncodingAndErrors(sys_stream, codeset, errors))
                Py_FatalError("Cannot set codeset of stdout");
        }

        sys_stream = PySys_GetObject("stderr");
        if ((overridden || isatty_no_error(sys_stream)) &&
            PyFile_Check(sys_stream)) {
            if (!PyFile_SetEncodingAndErrors(sys_stream, codeset, errors))
                Py_FatalError("Cannot set codeset of stderr");
        }

        if (free_codeset)
            free(codeset);
    }
}