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Command-Line Interface (CLI)

This section describes the command-line arguments and subcommands available in the Basis framework. The commands are designed to provide information on topics, schemas, and the ability to launch processes defined in YAML files.

Global Options​

  • --port: Specifies the port number that the Basis coordinator is listening on.
    • Default: 1492
    • Example: --port 8080

Commands​

topic Command​

The topic command provides information about topics within the Basis system.

  • ls: Lists the available topics.

    • Example: basis topic ls

  • info: Retrieves information about a specific topic.

    • Argument: topic (The name of the topic)
    • Example: basis topic info /example_topic

  • print: Prints messages on a specified topic.

    • Argument: topic (The name of the topic)
    • Option: -n (Number of messages to print, defaults to infinite)
    • Option: --json or -j (If specified, messages are output in JSON format)
    • Example: basis topic print /example_topic -n 10 --json

  • hz: Monitors the receive rate (frequency) of messages on a specified topic.

    • Argument: topic (The name of the topic)
    • Example: basis topic hz /example_topic

schema Command​

The schema command provides information about schemas used within the Basis system.

  • print: Prints the structure of a specified schema.
    • Argument: schema (The name of the schema)
    • Example: basis schema print example_schema

launch Command​

The launch command is used to start processes defined in YAML configuration files.

  • Option: --process (Specifies a particular process within the YAML file to launch. Defaults to an empty string, meaning all processes will be launched.)

    • Example: basis launch --process process_name example_launch.yaml

  • Option: --sim (Indicates whether to wait for simulated time messages. Defaults to false, but can be enabled with true.)

    • Example: basis launch --sim example_launch.yaml

  • Argument: launch_yaml (The path to the YAML file that defines the processes to launch.)

    • Example: basis launch example_launch.yaml

Usage Examples​

  1. To list all available topics:

    basis topic ls

  2. To print information about a specific topic:

    basis topic info /camera

  3. To launch a process defined in a YAML file with simulation enabled:

    basis launch --sim example.yaml

  4. To print 5 messages from a topic in JSON format:

    basis topic print /example_topic -n 5 --json