python-howto.txt

PYTHON BINDINGS
----------------

This is a brief howto for using the lttng-tools Python module.

By default, the Python bindings are not installed.
If you wish the Python bindings, you can configure with the
--enable-python-bindings option during the installation procedure:

  $ ./configure --enable-python-bindings

The Python module is automatically generated using SWIG, therefore the
swig2.0 package on Debian/Ubuntu is requied.

Once installed, the Python module can be used by importing it in Python.
In the Python interpreter:

  >>> import lttng

Example:
----------------

Quick example using Python to trace with LTTng.

1) Run python

  $ python

2) Import the lttng module

  >>> import lttng

3) Create a session

  >>> lttng.create("session-name", "path/to/trace")

4) Create a handle for the tracing session and domain

  >>> domain = lttng.Domain()
  >>> domain.type = lttng.DOMAIN_KERNEL			*
  >>> handle = lttng.Handle("session-name", domain)

* This line is somewhat useless since domain.type is set to 0
  by default, the corresponding value of lttng.DOMAIN_KERNEL

5) Enable all Kernel events

  >>> event = lttng.Event()
  >>> event.type = lttng.EVENT_TRACEPOINT		*
  >>> event.loglevel_type = lttng.EVENT_LOGLEVEL_ALL	*
  >>> lttng.enable_event(handle, event, None)

* These two lines are somewhat useless since event.type
  and event.loglevel_type are by default set to 0, the
  corresponding value of lttng.EVENT_TRACEPOINT and
  lttng.EVENT_LOGLEVEL_ALL

5) Start tracing

  >>> lttng.start("session-name")

6) Stop tracing

  >>> lttng.stop("session-name")

7) Destroy the tracing session

  >>> lttng.destroy("session-name")

For an example script with more details, see extras/bindings/swig/python/tests/example.py