---
name: "babeltrace2-help"
section: "1"
platform: "linux"
package: "babeltrace2"
version: "2.1.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/babeltrace2-help"
---

# babeltrace2-help(1)

Get help for a Babeltrace 2 plugin or component class

## NAME

babeltrace2-help - Get help for a Babeltrace 2 plugin or component class

## SYNOPSIS

Get help for a Babeltrace 2 plugin:

```
babeltrace2 [GENERAL OPTIONS] help PLUGIN-NAME
```

Get help for a Babeltrace 2 component class:

```
babeltrace2 [GENERAL OPTIONS] help
            COMP-CLS-TYPE.PLUGIN-NAME.COMP-CLS-NAME
```

## DESCRIPTION

The **help** command prints the details and help text of either the Babeltrace 2 plugin named *PLUGIN-NAME* or the specific component class of type *COMP-CLS-TYPE* named *COMP-CLS-NAME* found in the plugin named *PLUGIN-NAME*.

See [**babeltrace2-intro**(7)](/babeltrace2-intro/7.md) 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.

See “EXAMPLES” for usage examples.

## OPTIONS

### General

You can use those options before the command name.

See [**babeltrace2**(1)](/babeltrace2/1.md) 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**

  Don’t search for plugins in **$HOME/.local/lib/babeltrace2/plugins**.

- **--omit-system-plugin-path**

  Don’t 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**.

### Command information

- **-h**, **--help**

  Show the command help and quit.

## EXAMPLES

**Example 1. Get help for a plugin and all its component classes.**

```
$ babeltrace2 help ctf
```

**Example 2. Get help for a specific source component class.**

```
$ babeltrace2 help source.ctf.fs
```

**Example 3. Get help for a specific sink component class.**

```
$ babeltrace2 help sink.text.pretty
```

## 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)](/babeltrace2/1.md) program and the project 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 initial log level of the Babeltrace 2 library to be *LVL*.

If this environment variable is set, then 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, then 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, then 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 the log level of the log level **babeltrace2** CLI to be *LVL*.

If this environment variable is set, then 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)](/babeltrace2-convert/1.md) 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 \<https://bugs.lttng.org/projects/babeltrace\>).

## RESOURCES

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

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

This command is part of the Babeltrace 2 project.

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

## SEE ALSO

[**babeltrace2-intro**(7)](/babeltrace2-intro/7.md), [**babeltrace2**(1)](/babeltrace2/1.md), [**babeltrace2-list-plugins**(1)](/babeltrace2-list-plugins/1.md)
