Function npy_PyFile_Dup2

numpy/core/include/numpy/npy_3kcompat.h:211–326

* Get a FILE* handle to the file represented by the Python object */

 * Get a FILE* handle to the file represented by the Python object
 */
static inline FILE*
npy_PyFile_Dup2(PyObject *file, char *mode, npy_off_t *orig_pos)
{
    int fd, fd2, unbuf;
    Py_ssize_t fd2_tmp;
    PyObject *ret, *os, *io, *io_raw;
    npy_off_t pos;
    FILE *handle;

    /* For Python 2 PyFileObject, use PyFile_AsFile */
#if !defined(NPY_PY3K)
    if (PyFile_Check(file)) {
        return PyFile_AsFile(file);
    }
#endif

    /* Flush first to ensure things end up in the file in the correct order */
    ret = PyObject_CallMethod(file, "flush", "");
    if (ret == NULL) {
        return NULL;
    }
    Py_DECREF(ret);
    fd = PyObject_AsFileDescriptor(file);
    if (fd == -1) {
        return NULL;
    }

    /*
     * The handle needs to be dup'd because we have to call fclose
     * at the end
     */
    os = PyImport_ImportModule("os");
    if (os == NULL) {
        return NULL;
    }
    ret = PyObject_CallMethod(os, "dup", "i", fd);
    Py_DECREF(os);
    if (ret == NULL) {
        return NULL;
    }
    fd2_tmp = PyNumber_AsSsize_t(ret, PyExc_IOError);
    Py_DECREF(ret);
    if (fd2_tmp == -1 && PyErr_Occurred()) {
        return NULL;
    }
    if (fd2_tmp < INT_MIN || fd2_tmp > INT_MAX) {
        PyErr_SetString(PyExc_IOError,
                        "Getting an 'int' from os.dup() failed");
        return NULL;
    }
    fd2 = (int)fd2_tmp;

    /* Convert to FILE* handle */
#ifdef _WIN32
    NPY_BEGIN_SUPPRESS_IPH
    handle = _fdopen(fd2, mode);
    NPY_END_SUPPRESS_IPH
#else