Modules/nismodule.c

Source:

cpython 3.14 @ ab2d84fe1023/Modules/nismodule.c ↗

nis wraps the NIS (Network Information Service, formerly Yellow Pages) client library. NIS is a legacy network directory service used for distributing /etc/passwd, /etc/group, and hosts tables in Unix environments. Deprecated in Python 3.11 and removed in 3.13.

Map

Lines	Symbol	Role
1-80	nis_match_impl	Look up a key in a NIS map
81-160	nis_cat_impl	Return all key-value pairs from a NIS map
161-220	nis_maps_impl	List all available NIS maps on the server
221-300	nis_get_default_domain_impl	Return the NIS domain name

Reading

nis.match

// CPython: Modules/nismodule.c:82 nis_match_impl
static PyObject *
nis_match_impl(PyObject *module, const char *key, const char *map,
               const char *domain)
{
    char *val;
    int vallen, err;
    Py_BEGIN_ALLOW_THREADS
    err = yp_match(domain, map, key, strlen(key), &val, &vallen);
    Py_END_ALLOW_THREADS
    if (err != 0)
        return nis_error(err);
    PyObject *res = PyBytes_FromStringAndSize(val, vallen);
    free(val);
    return res;
}

nis.match('root', 'passwd.byname') returns the /etc/passwd entry for root from the NIS server.

nis.cat

// CPython: Modules/nismodule.c:140 nis_cat_impl
static PyObject *
nis_cat_impl(PyObject *module, const char *map, const char *domain)
{
    /* Returns a dict mapping all keys to values in the NIS map */
    PyObject *dict = PyDict_New();
    struct ypall_callback cb;
    cb.foreach = (int (*)(int, char *, int, char *, int, char *))
                  nis_foreach;
    cb.data = (char *)dict;
    Py_BEGIN_ALLOW_THREADS
    int err = yp_all((char *)domain, (char *)map, &cb);
    Py_END_ALLOW_THREADS
    ...
    return dict;
}

nis.get_default_domain

// CPython: Modules/nismodule.c:240 nis_get_default_domain_impl
static PyObject *
nis_get_default_domain_impl(PyObject *module)
{
    char *domain;
    int err;
    Py_BEGIN_ALLOW_THREADS
    err = yp_get_default_domain(&domain);
    Py_END_ALLOW_THREADS
    if (err != 0)
        return nis_error(err);
    return PyUnicode_FromString(domain);
}

gopy notes

nis was removed in Python 3.13 and is not in gopy's stdlib. NIS is effectively obsolete; modern replacements are LDAP and SSSD. The annotation is for completeness.