[ltt-dev] [RFC] lttng-tools command line interface

[Mathieu Desnoyers]

Hi,

I'm currently discussing with David Goulet about the lttng command line
UI, and here is what we are coming up with:

We plan to go for a git-alike UI:

  lttng command [options]

Where command can be one of the following, and the options are
per-command:

(note: in the description below, options between [ ] are implied by
default)

* Basic options

  -v, --verbose                # Verbose mode
  -q, --quiet                  # Quiet mode
      --help                   # Show help
      --group NAME             # Unix tracing group name. (default: tracing)
      --no-sessiond            # Don't spawn a session daemon
      --sessiond-path          # Session daemon full path
  help/--help/-h               # list LTTng commands

* List interfaces:

lttng list [--help]        # show list options
lttng list --events        # list all available instrumentation
lttng list --kernel        # list kernel instrumentation
lttng list --pid n         # list userspace app instrumentation by pid
lttng list command_name    # list userspace app instrumentation by command
lttng list --app           # list traceable user-space applications/pids
lttng list --sessions      # list tracing sessions

* Show version

lttng version [--help]     # show lttng-tools version and version options
lttng version --kernel     # show kernel lttng version
lttng version --pid n      # show kernel lttng version
lttng version command_name # show lttng versions for app by command

* Tracing session control

lttng create [--session name] # create a tracing session
     [--output path]          # optionally specify the output path 
     [--name name]            # optional session name (default provided)

---> This command prints
     "Working directory of created session is /path/to/name. Change your"
     "current working directory to interact with this session."

---> All the following commands use the current working directory
     .lttng/config file to keep track of the session on which actions
     should be applied.

lttng destroy [--session name] # teardown a tracing session
lttng start [--session name]   # start tracing for a session
lttng stop [--session name]    # stop tracing for a session


(note in manpage (warning) about --all and cmd_name:
"WARNING: this may noticeably slow down your system!")
lttng add-channel name --kernel [options]
lttng add-channel name --userspace [--all/--pid n/cmd_name] [options]
  available options:
  --discard (default)
  --overwrite
  --subbuf_size
  --num_subbuf
  --switch_timer_interval
  --read_timer_interval

lttng config --kernel --channel name
lttng config --channel name [--all/--pid n/cmd_name]

(note: no channel name specified creates a "default" channel)
lttng add-event name --kernel [--channel name]
lttng add-event name --userspace [--channel name] [--all/--pid n/cmd_name]
  available options, either:
  --tracepoint (default)
  --marker
  --kprobe address
  --function
  (support list of names: name1,name2,name3... all with the same
   options)
lttng enable-event name --kernel [--channel name]
lttng disable-event name --kernel [--channel name]
lttng enable-event name --userspace [--channel name] [--all/--pid n/cmd_name]
lttng disable-event name --userspace [--channel name] [--all/--pid n/cmd_name]

lttng add-context name --kernel [--event name] [--channel name] --type context_type [context options]
lttng add-context name --userspace [--event name] [--channel name] [--all/--pid n/cmd_name] --type context_type [context options]

Comments are immensely welcome!

Thanks,

Mathieu

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com