LTTng » LTTng-tools

Actually, lttng --list-commands still returns enable-consumer and disable-consumer, so the _lttng_cmd_*able_consumer() should be kept but their case $prev can be removed.

I also find command-line completion fails for the enable-channel, enable-event and disable-channel commands because it is looking for e.g. _lttng_cmd_enable_channel but lttng-bash_completion supplies _lttng_cmd_enablechannel.

Here is a crude _lttng_complete_sessions():

_lttng_complete_sessions() {
    # TODO, maybe have a lttng list --simple or something like that
    local sessions_opts
#    sessions_opts=$(lttng list --simple)
    sessions_opts=$(lttng list | cut -s -d")" -f2 | cut -d"(" -f1)
    COMPREPLY=( $(compgen -W "${sessions_opts}" -- $cur) )
    return
}

The generated sessions_opts contains extra blanks on either side of the session names, but bash completion takes care of those.

And here is a crude _lttng_cmd_snapshot():

_lttng_cmd_snapshot() {
    local snapshot_opts
    snapshot_opts=$(lttng snapshot --list-options)
    # TODO We need a 'snapshot --list-actions' to get the list of possible actions
    local snapshot_acts
#    snapshot_acts=$(lttng snapshot --list-actions)
    snapshot_acts="add-output del-output list-output record" 

    case $prev in
    --session|-s)
        _lttng_complete_sessions
        return
        ;;
    esac

    case $cur in
    -*)
        COMPREPLY=( $(compgen -W "${snapshot_opts}" -- $cur) )
        return
        ;;
    *)
        COMPREPLY=( $(compgen -W "${snapshot_acts}" -- $cur) )
        return
        ;;
    esac
}

Until lttng snapshot --list-actions is implemented, this lttng-bash_completion function will need to be manually updated every time a snapshot action is renamed, added or deleted.

Finally, I would add a call to _lttng_complete_sessions in _lttng_cmd_list() and _lttng_cmd_set_session():

_lttng_cmd_list() {
    local list_opts
    list_opts=$(lttng list --list-options)

    case $prev in
    --channel|-c)
        return
        ;;
    esac

    case $cur in
    -*)
        COMPREPLY=( $(compgen -W "${list_opts}" -- $cur) )
        return
        ;;
    *)
        _lttng_complete_sessions
        ;;
    esac
}

_lttng_cmd_set_session() {
    local set_session_opts
    set_session_opts=$(lttng set-session --list-options)

    case $cur in
    -*)
        COMPREPLY=( $(compgen -W "${set_session_opts}" -- $cur) )
        return
        ;;
    *)
        _lttng_complete_sessions
        ;;
    esac
}

It may also make sense to add a similar call to _lttng_complete_sessions in _lttng_create(), just so the user knows which session names are already taken.

My proposal for _lttng_complete_sessions() above works fine with the local session daemon, but it will not give the correct session listing when using 'sudo -H lttng ...' because the $(lttng list | cut ...) command is not run as root. For example, if the local daemon has a 'local' session and the root daemon has a 'kernel' session, auto-completion of 'sudo -H list' will propose just 'local'.

The funny thing is, this "bug" would also crop up if we had an lttng list --simple implementation. It is probably unfixable because bash auto-completion is not aware that the user intends to use 'sudo' ($COMP_CWORDS[0] returns 'lttng').