patch #1668: clarify envvar docs; rename THREADDEBUG to PYTHONTHREADDEBUG.
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index b113c8f..a34666d 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -335,6 +335,8 @@
Environment variables
---------------------
+These environment variables influence Python's behavior.
+
.. envvar:: PYTHONHOME
Change the location of the standard Python libraries. By default, the
@@ -350,7 +352,7 @@
.. envvar:: PYTHONPATH
- Augments the default search path for module files. The format is the same as
+ Augment the default search path for module files. The format is the same as
the shell's :envvar:`PATH`: one or more directory pathnames separated by
colons. Non-existent directories are silently ignored.
@@ -400,6 +402,9 @@
If this is set to a non-empty string it is equivalent to specifying the
:option:`-i` option.
+ This variable can also be modified by Python code using :data:`os.environ`
+ to force inspect mode on program termination.
+
.. envvar:: PYTHONUNBUFFERED
@@ -422,7 +427,40 @@
.. envvar:: PYTHONDONTWRITEBYTECODE
- If given, Python won't try to write ``.pyc`` or ``.pyo`` files on the
+ If this is set, Python won't try to write ``.pyc`` or ``.pyo`` files on the
import of source modules.
.. versionadded:: 2.6
+
+
+.. envvar:: PYTHONEXECUTABLE
+
+ If this environment variable is set, ``sys.argv[0]`` will be set to its
+ value instead of the value got through the C runtime. Only works on
+ MacOS X.
+
+
+Debug-mode variables
+^^^^^^^^^^^^^^^^^^^^
+
+Setting these variables only has an effect in a debug build of Python, that is,
+if Python was configured with the :opt:`--with-pydebug` build option.
+
+.. envvar:: PYTHONTHREADDEBUG
+
+ If set, Python will print debug threading debug info.
+
+ .. versionchanged:: 2.6
+ Previously, this variable was called ``THREADDEBUG``.
+
+.. envvar:: PYTHONDUMPREFS
+
+ If set, Python will dump objects and reference counts still alive after
+ shutting down the interpreter.
+
+
+.. envvar:: PYTHONMALLOCSTATS
+
+ If set, Python will print memory allocation statistics every time a new
+ object arena is created, and on shutdown.
+