Terminal Interface
==================

While :ref:`running one of the pilot binaries <Running>` you can, at any time,
hit the ``<Enter>`` key which interrupts the log output
and gives you a terminal prompt. You can now execute one of several
commands.
Type it in and press ``<Enter>`` to execute.

Commands that have an output keep the log paused after execution, to give you
time to look at it. The log continues when you press ``<Enter>`` again.

The following commands are currently available:

* ``quit`` exits the application
* ``debug [level]`` changes the level of the output. The bigger the number, the
  more log messages you get.
* ``errors`` outputs the last error messages
* ``topic [expr]`` searches all topic names for ``expr``.
  If there is no exact match, all topics that ``expr`` is a prefix of are shown.
  If there are none, all matches are shown.
* ``module [expr]`` lists all modules that ``expr`` matches on. If there is an
  exact match, it displays more detailed information for that module.
* ``grep <expr>`` restricts terminal output to messages that contain ``expr``.
* ``journal [expr]`` does the same as ``grep`` but first shows all past log
  messages that contain ``expr``.
* ``spy [expr]`` does the same as ``dump`` but without the actual message content.
* ``dump [expr]`` outputs the messages on all topics that match ``expr``.
* ``htop [field]`` shows the modules with the highest CPU load in a table that
  refreshes regularly. ``field`` can be ``avg`` to change the sorting.
* ``exec <module>[.method [args...]]`` and ``call <module>[.method [args...]]``
  invoke the given method of the given module with the given arguments.
  ``exec`` waits for the command to finish and displays the result while ``call``
  performs an asynchronous call.
  If no method is given, a list of method signatures for the module is shown.


While typing,
the terminal will provide you with suggestions for the command and
possible arguments. Press the ``<Tab>`` key to complete, press it twice to get
a list of suggestions. You can also use the up and down arrows the scroll through
the history of past commands.