babeltrace2-query(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | ENVIRONMENT VARIABLES | FILES | EXIT STATUS | BUGS | RESOURCES | AUTHORS | COPYRIGHT | SEE ALSO | COLOPHON

BABELTRACE2-QUERY(1)       Babeltrace 2 manual      BABELTRACE2-QUERY(1)

NAME         top

       babeltrace2-query - Query an object from a Babeltrace 2 component
       class

SYNOPSIS         top

       babeltrace2 [GENERAL OPTIONS] query [--params=PARAMS]
                   COMP-CLS-TYPE.PLUGIN-NAME.COMP-CLS-NAME OBJECT

DESCRIPTION         top

       The query command queries the object named OBJECT from the
       component class named COMP-CLS-NAME of the type COMP-CLS-TYPE
       found in the Babeltrace 2 plugin named PLUGIN-NAME and prints the
       results.

       See babeltrace2-intro(7) to learn more about the Babeltrace 2
       project and its core concepts.

       The available values for COMP-CLS-TYPE are:

       source, src
           Source component class.

       filter, flt
           Filter component class.

       sink
           Sink component class.

       The exact object names and the parameters that a given component
       class expects are described in its own documentation.
       babeltrace2-help(1) can generally provide this information.

       You can use the --params option to pass parameters to the
       component class’s query operation.

       The output of the query command can look like YAML (see
       <https://yaml.org/>), but it’s not guaranteed to be
       YAML-compliant.

       See “EXAMPLES” for usage examples.

OPTIONS         top

   General
       You can use those options before the command name.

       See babeltrace2(1) for more details.

       -d, --debug
           Legacy option: this is equivalent to --log-level=TRACE.

       -l LVL, --log-level=LVL
           Set the log level of all known Babeltrace 2 loggers to LVL.

       --omit-home-plugin-path
           Do not search for plugins in
           $HOME/.local/lib/babeltrace2/plugins.

       --omit-system-plugin-path
           Do not search for plugins in
           /usr/local/lib/babeltrace2/plugins.

       --plugin-path=PATH[:PATH]...
           Add PATH to the list of paths in which plugins can be found.

       -v, --verbose
           Legacy option: this is equivalent to --log-level=INFO.

   Query parameters
       -p PARAMS, --params=PARAMS
           Set the query parameters to PARAMS.

           The format of PARAMS is a comma-separated list of NAME=VALUE
           assignments:

               NAME=VALUE[,NAME=VALUE]...

           NAME
               Parameter name (C identifier plus the :, ., and -
               characters).

           VALUE
               One of:

               •   null, nul, NULL: null value.

               •   true, TRUE, yes, YES: true boolean value.

               •   false, FALSE, no, NO: false boolean value.

               •   Binary (0b prefix), octal (0 prefix), decimal, or
                   hexadecimal (0x prefix) unsigned (with + prefix) or
                   signed 64-bit integer.

               •   Double precision floating point number (scientific
                   notation is accepted).

               •   Unquoted string with no special characters, and not
                   matching any of the null and boolean value symbols
                   above.

               •   Double-quoted string (accepts escape characters).

               •   Array, formatted as an opening [, a comma-separated
                   list of VALUE, and a closing ].

               •   Map, formatted as an opening {, a comma-separated
                   list of NAME=VALUE assignments, and a closing }.

               You may put whitespaces around the individual =
               (assignment), , (separator), [ (array beginning), ]
               (array end), { (map beginning), and } (map end)
               characters.

           Example:

               --params='many=null, fresh=yes, condition=false, squirrel=-782329,
                         play=+23, observe=3.14, simple=beef,
                         needs-quotes="some string",
                         escape.chars-are:allowed="a \" quote",
                         things=[1, "hello", 2.71828],
                         frog={slow=2, bath=[bike, 23], blind=NO}'

               Important
               Like in the example above, make sure to single-quote the
               whole argument when you run this command from a shell, as
               it can contain many special characters.

   Command information
       -h, --help
           Show the command’s help and quit.

EXAMPLES         top

       Example 1. Query the available tracing sessions of a local LTTng
       relay daemon.

           $ babeltrace2 query src.ctf.lttng-live sessions \
                               --params='url="net://localhost"'

       Example 2. Query the metadata info (includes the decoded plain
       text) of a CTF trace located on the local file system.

           $ babeltrace2 query src.ctf.fs metadata-info \
                               --params='path="/path/to/trace"'

       Example 3. Query the trace infos of a CTF trace located on the
       local file system.

           $ babeltrace2 query src.ctf.fs babeltrace.trace-infos \
                               --params='path="/path/to/trace"'

       Example 4. Query some object from a sink component class without
       parameters.

           $ babeltrace2 query sink.my-plugin.my-sink some-object

ENVIRONMENT VARIABLES         top

   Babeltrace 2 library
       BABELTRACE_EXEC_ON_ABORT=CMDLINE
           Execute the command line CMDLINE, as parsed like a UNIX 98
           shell, when any part of the Babeltrace 2 project unexpectedly
           aborts.

           The application only aborts when the executed command
           returns, ignoring its exit status.

           This environment variable is ignored when the application has
           the setuid or the setgid access right flag set.

       BABELTRACE_TERM_COLOR=(AUTO | NEVER | ALWAYS)
           Force the terminal color support for the babeltrace2(1)
           program and the project’s plugins.

           The available values are:

           AUTO
               Only emit terminal color codes when the standard output
               and error streams are connected to a color-capable
               terminal.

           NEVER
               Never emit terminal color codes.

           ALWAYS
               Always emit terminal color codes.

       BABELTRACE_TERM_COLOR_BRIGHT_MEANS_BOLD=0
           Set to 0 to emit SGR (see
           <https://en.wikipedia.org/wiki/ANSI_escape_code>) codes 90 to
           97 for bright colors instead of bold (SGR code 1) and
           standard color codes (SGR codes 30 to 37).

       BABELTRACE_PLUGIN_PATH=PATHS
           Set the list of directories, in order, in which dynamic
           plugins can be found before other directories are considered
           to PATHS (colon-separated, or semicolon on Windows).

       LIBBABELTRACE2_DISABLE_PYTHON_PLUGINS=1
           Disable the loading of any Babeltrace 2 Python plugin.

       LIBBABELTRACE2_INIT_LOG_LEVEL=LVL
           Force the Babeltrace 2 library’s initial log level to be LVL.

           If this environment variable is set, it overrides the log
           level set by the --log-level option for the Babeltrace 2
           library logger.

           The available values for LVL are:

           NONE, N
               Logging is disabled.

           FATAL, F
               Severe errors that lead the execution to abort
               immediately.

               This level should be enabled in production.

           ERROR, E
               Errors that might still allow the execution to continue.

               Usually, once one or more errors are reported at this
               level, the application, plugin, or library won’t perform
               any more useful task, but it should still exit cleanly.

               This level should be enabled in production.

           WARN, WARNING, W
               Unexpected situations which still allow the execution to
               continue.

               This level should be enabled in production.

           INFO, I
               Informational messages that highlight progress or
               important states of the application, plugins, or library.

               This level can be enabled in production.

           DEBUG, D
               Debugging information, with a higher level of details
               than the TRACE level.

               This level should NOT be enabled in production.

           TRACE, T
               Low-level debugging context information.

               This level should NOT be enabled in production.

       LIBBABELTRACE2_NO_DLCLOSE=1
           Make the Babeltrace 2 library leave any dynamically loaded
           modules (plugins and plugin providers) open at exit. This can
           be useful for debugging purposes.

       LIBBABELTRACE2_PLUGIN_PROVIDER_DIR=DIR
           Set the directory from which the Babeltrace 2 library
           dynamically loads plugin provider shared objects to DIR.

           If this environment variable is set, it overrides the default
           plugin provider directory.

   Babeltrace 2 Python bindings
       BABELTRACE_PYTHON_BT2_LOG_LEVEL=LVL
           Force the Babeltrace 2 Python bindings log level to be LVL.

           If this environment variable is set, it overrides the log
           level set by the --log-level option for the Python bindings
           logger.

           The available values for LVL are:

           NONE, N
               Logging is disabled.

           FATAL, F
               Severe errors that lead the execution to abort
               immediately.

               This level should be enabled in production.

           ERROR, E
               Errors that might still allow the execution to continue.

               Usually, once one or more errors are reported at this
               level, the application, plugin, or library won’t perform
               any more useful task, but it should still exit cleanly.

               This level should be enabled in production.

           WARN, WARNING, W
               Unexpected situations which still allow the execution to
               continue.

               This level should be enabled in production.

           INFO, I
               Informational messages that highlight progress or
               important states of the application, plugins, or library.

               This level can be enabled in production.

           DEBUG, D
               Debugging information, with a higher level of details
               than the TRACE level.

               This level should NOT be enabled in production.

           TRACE, T
               Low-level debugging context information.

               This level should NOT be enabled in production.

   CLI
       BABELTRACE_CLI_LOG_LEVEL=LVL
           Force babeltrace2 CLI’s log level to be LVL.

           If this environment variable is set, it overrides the log
           level set by the --log-level option for the CLI logger.

           The available values for LVL are:

           NONE, N
               Logging is disabled.

           FATAL, F
               Severe errors that lead the execution to abort
               immediately.

               This level should be enabled in production.

           ERROR, E
               Errors that might still allow the execution to continue.

               Usually, once one or more errors are reported at this
               level, the application, plugin, or library won’t perform
               any more useful task, but it should still exit cleanly.

               This level should be enabled in production.

           WARN, WARNING, W
               Unexpected situations which still allow the execution to
               continue.

               This level should be enabled in production.

           INFO, I
               Informational messages that highlight progress or
               important states of the application, plugins, or library.

               This level can be enabled in production.

           DEBUG, D
               Debugging information, with a higher level of details
               than the TRACE level.

               This level should NOT be enabled in production.

           TRACE, T
               Low-level debugging context information.

               This level should NOT be enabled in production.

       BABELTRACE_CLI_WARN_COMMAND_NAME_DIRECTORY_CLASH=0
           Disable the warning message which babeltrace2-convert(1)
           prints when you convert a trace with a relative path that’s
           also the name of a babeltrace2 command.

       BABELTRACE_DEBUG=1
           Legacy variable: equivalent to setting the --log-level option
           to TRACE.

       BABELTRACE_VERBOSE=1
           Legacy variable: equivalent to setting the --log-level option
           to INFO.

FILES         top

       $HOME/.local/lib/babeltrace2/plugins
           User plugin directory.

       /usr/local/lib/babeltrace2/plugins
           System plugin directory.

       /usr/local/lib/babeltrace2/plugin-providers
           System plugin provider directory.

EXIT STATUS         top

       0 on success, 1 otherwise.

BUGS         top

       If you encounter any issue or usability problem, please report it
       on the Babeltrace bug tracker (see
       <https://bugs.lttng.org/projects/babeltrace>).

RESOURCES         top

       The Babeltrace project shares some communication channels with
       the LTTng project (see <https://lttng.org/>).

       •   Babeltrace website (see <https://babeltrace.org/>)

       •   Mailing list (see <https://lists.lttng.org>) for support and
           development: lttng-dev@lists.lttng.org

       •   IRC channel (see <irc://irc.oftc.net/lttng>): #lttng on
           irc.oftc.net

       •   Bug tracker (see
           <https://bugs.lttng.org/projects/babeltrace>)

       •   Git repository (see
           <https://git.efficios.com/?p=babeltrace.git>)

       •   GitHub project (see <https://github.com/efficios/babeltrace>)

       •   Continuous integration (see
           <https://ci.lttng.org/view/Babeltrace/>)

       •   Code review (see
           <https://review.lttng.org/q/project:babeltrace>)

AUTHORS         top

       The Babeltrace 2 project is the result of hard work by many
       regular developers and occasional contributors.

       The current project maintainer is Jérémie Galarneau
       <mailto:jeremie.galarneau@efficios.com>.

COPYRIGHT         top

       This command is part of the Babeltrace 2 project.

       Babeltrace is distributed under the MIT license (see
       <https://opensource.org/licenses/MIT>).

SEE ALSO         top

       babeltrace2-intro(7), babeltrace2(1)

COLOPHON         top

       This page is part of the babeltrace (trace read and write
       libraries and a trace converter) project.  Information about the
       project can be found at ⟨http://www.efficios.com/babeltrace⟩.  If
       you have a bug report for this manual page, send it to
       lttng-dev@lists.lttng.org.  This page was obtained from the
       project's upstream Git repository
       ⟨git://git.efficios.com/babeltrace.git⟩ on 2021-08-27.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-08-20.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Babeltrace 2.1.0-rc1        14 September 2019       BABELTRACE2-QUERY(1)

Pages that refer to this page: babeltrace2(1)babeltrace2-intro(7)babeltrace2-query-babeltrace.support-info(7)babeltrace2-query-babeltrace.trace-infos(7)