gh-130160: use .. program:: directive for documenting doctest CLI

Doc/library/cmdline.rst

@@ -13,7 +13,7 @@ The following modules have a command-line interface.
 * :mod:`cProfile`: see :ref:`profile <profile-cli>`
 * :ref:`difflib <difflib-interface>`
 * :ref:`dis <dis-cli>`
-* :mod:`doctest`
+* :ref:`doctest <doctest-cli>`
 * :mod:`!encodings.rot_13`
 * :mod:`ensurepip`
 * :mod:`filecmp`

Doc/library/doctest.rst

@@ -177,15 +177,8 @@ prohibit it by passing ``verbose=False``.  In either of those cases,
 ``sys.argv`` is not examined by :func:`testmod` (so passing ``-v`` or not
 has no effect).
 
-There is also a command line shortcut for running :func:`testmod`.  You can
-instruct the Python interpreter to run the doctest module directly from the
-standard library and pass the module name(s) on the command line::
-
-   python -m doctest -v example.py
-
-This will import :file:`example.py` as a standalone module and run
-:func:`testmod` on it.  Note that this may not work correctly if the file is
-part of a package and imports other submodules from that package.
+There is also a command line shortcut for running :func:`testmod`, see section
+:ref:`doctest-cli`.
 
 For more information on :func:`testmod`, see section :ref:`doctest-basic-api`.
 
@@ -248,16 +241,52 @@ Like :func:`testmod`, :func:`testfile`'s verbosity can be set with the
 ``-v`` command-line switch or with the optional keyword argument
 *verbose*.
 
-There is also a command line shortcut for running :func:`testfile`.  You can
-instruct the Python interpreter to run the doctest module directly from the
-standard library and pass the file name(s) on the command line::
+There is also a command line shortcut for running :func:`testfile`, see section
+:ref:`doctest-cli`.
 
-   python -m doctest -v example.txt
+For more information on :func:`testfile`, see section :ref:`doctest-basic-api`.
 
-Because the file name does not end with :file:`.py`, :mod:`doctest` infers that
-it must be run with :func:`testfile`, not :func:`testmod`.
 
-For more information on :func:`testfile`, see section :ref:`doctest-basic-api`.
+.. _doctest-cli:
+
+Command-line Usage
+------------------
+
+The :mod:`doctest` module can be invoked as a script from the command line:
+
+.. code-block:: bash
+
+   python -m doctest [-v] [-o OPTION] [-f] file [file ...]
+
+.. program:: doctest
+
+.. option:: -v, --verbose
+
+   Detailed report of all examples tried is printed to standard output,
+   along with assorted summaries at the end::
+
+      python -m doctest -v example.py
+
+   This will import :file:`example.py` as a standalone module and run
+   :func:`testmod` on it.  Note that this may not work correctly if the file is
+   part of a package and imports other submodules from that package.
+   If the file name does not end with :file:`.py`, :mod:`doctest` infers that
+   it must be run with :func:`testfile`, not :func:`testmod`::
+
+      python -m doctest -v example.txt
+
+.. option:: -o, --option <option>
+
+   Option flags control various aspects of doctest's behavior, see section
+   :ref:`doctest-options`.
+
+   .. versionadded:: 3.4
+
+.. option:: -f, --fail-fast
+
+   This is shorthand for ``-o FAIL_FAST``.
+
+   .. versionadded:: 3.4
 
 
 .. _doctest-how-it-works:
@@ -540,9 +569,6 @@ Symbolic names for the flags are supplied as module constants, which can be
 The names can also be used in :ref:`doctest directives <doctest-directives>`,
 and may be passed to the doctest command line interface via the ``-o`` option.
 
-.. versionadded:: 3.4
-   The ``-o`` command line option.
-
 The first group of options define test semantics, controlling aspects of how
 doctest decides whether actual output matches an example's expected output:
 
@@ -682,11 +708,6 @@ The second group of options controls how test failures are reported:
    1.  This flag may be useful during debugging, since examples after the first
    failure won't even produce debugging output.
 
-   The doctest command line accepts the option ``-f`` as a shorthand for ``-o
-   FAIL_FAST``.
-
-   .. versionadded:: 3.4
-
 
 .. data:: REPORTING_FLAGS