[lttng-dev] lttng command line user-friendliness

Woegerer, Paul Paul_Woegerer at mentor.com
Mon Sep 10 11:39:09 EDT 2012

On 09/10/2012 05:00 PM, David Goulet wrote:
> Issuing a sequence of commands like:
> lttng create lttng enable-event -u -a lttng start
> my_foobar_traced_application 1 2 3 lttng stop lttng destroy
> Small note here that the "destroy" is not needed. The stop forces a
> subbuffer switch meaning that the current data collected is written to
> the trace files.

Agreed, "destroy" is pointless. Also the user would want to have the 
result of "lttng record" visible when it runs "lttng list" afterwards.

> I would however encourage everyone on this list who is willing to
> continue this thread in order to come up with a small RFC for the command.
> RFC/Discussion:
> lttng record [--session-name <name>] [--session-template
> <session_template_file>]  -- <command> [<options>]
> Either "trace" or "record", I guess it's a simple aesthetic choice
> here :).

Using command name "trace" makes more sense. "record" does not go so 
well with "--live" (where nothing gets actually recorded).

So far [--session-template <session_template_file>] leaves open where to 
look for session_template_files if no absolute path is given. It might 
be good to also have a user specific directory (e.g. 
.lttng/session-templates) in addition to a system wide directory (e.g. 


> With more options here to set either a custom destination or live
> trace. What's the default? (no opts given). I would personally go for
> a default one being to record in the session default trace files and
> add a "-l" for the live.
> 	-o, --output=DST
> 	-l, --live
> Add a domain option where nothing enables kernel AND ust or else the
> command can take either -u or -k.
> Please, contribute to this, no bad ideas, only bad answers! :)
> Cheers and thanks Paul for comment!
> David
>> Thanks, Paul
> N+jLVU/JjMuzjpQluD+1Xe3O9yLDu/mEqGAddYBQ5RnkHS7DveFwfY697nESqJPR
> qV0Y3ajbIC30WMrnweZSypsj9xAv33ZzFn4C/DuYIylicqpcX8mxcMgLzI9duoRQ
> /kxOqIeBLvl5C/pFSR55vki3fxhHPg67f2S9TgFDiBEPmaL0UkxpfOaB3G86Bj8z
> Kp7oKCCbQzv0R3J4BlcNRNUXKTClo3Qjb/ZyWGgFwwErZJoADcd+osvIU9raA7MY
> yEEExx5t4OMjEyrb3eqJgihH+xMx6eW1275vz2TV4ayBIg1YuJrIzUY/zgVkYn0=
> =f6QB

Paul Woegerer | SW Development Engineer

Mentor Embedded(tm) | Prinz Eugen Straße 72/2/4, Vienna, 1040 Austria
Nucleus® | Linux® | Android(tm) | Services | UI | Multi-OS

Android is a trademark of Google Inc. Use of this trademark is subject to Google Permissions.
Linux is the registered trademark of Linus Torvalds in the U.S. and other countries.

More information about the lttng-dev mailing list