BABELTRACE2-QUERY(1) Babeltrace 2 manual BABELTRACE2-QUERY(1)
NAME
babeltrace2-query - Query an object from a Babeltrace 2 component class
SYNOPSIS
babeltrace2 [GENERAL OPTIONS] query [--params=PARAMS]
COMP-CLS-TYPE.PLUGIN-NAME.COMP-CLS-NAME OBJECT
DESCRIPTION
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
), but it's not guaranteed to be YAML-compliant.
See "EXAMPLES" for usage examples.
OPTIONS
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/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:
o null, nul, NULL: null value.
o true, TRUE, yes, YES: true boolean value.
o false, FALSE, no, NO: false boolean value.
o Binary (0b prefix), octal (0 prefix), decimal, or
hexadecimal (0x prefix) unsigned (with + prefix) or signed
64-bit integer.
o Double precision floating point number (scientific notation
is accepted).
o Unquoted string with no special characters, and not
matching any of the null and boolean value symbols above.
o Double-quoted string (accepts escape characters).
o Array, formatted as an opening [, a comma-separated list of
VALUE, and a closing ].
o 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
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
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
) 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
$HOME/.local/lib/babeltrace2/plugins
User plugin directory.
/usr/lib/babeltrace2/plugins
System plugin directory.
/usr/lib/babeltrace2/plugin-providers
System plugin provider directory.
EXIT STATUS
0 on success, 1 otherwise.
BUGS
If you encounter any issue or usability problem, please report it on
the Babeltrace bug tracker (see
).
RESOURCES
The Babeltrace project shares some communication channels with the
LTTng project (see ).
o Babeltrace website (see )
o Mailing list (see ) for support and
development: lttng-dev@lists.lttng.org
o IRC channel (see ): #lttng on
irc.oftc.net
o Bug tracker (see )
o Git repository (see )
o GitHub project (see )
o Continuous integration (see
)
o Code review (see )
AUTHORS
The Babeltrace 2 project is the result of hard work by many regular
developers and occasional contributors.
The current project maintainer is Jeremie Galarneau
.
COPYRIGHT
This command is part of the Babeltrace 2 project.
Babeltrace is distributed under the MIT license (see
).
SEE ALSO
babeltrace2-intro(7), babeltrace2(1)
Babeltrace 2.0.4 14 September 2019 BABELTRACE2-QUERY(1)