Bazel Command Examples (with examples)

1: Building a Target

To build a specific target in a workspace, you can use the bazel build target command. This command will compile the code and generate the corresponding output files.

Code:

bazel build //path/to/target

Motivation: This command is useful when you want to compile and build a specific target in your workspace. It allows you to specify the target with its path, which can be helpful when you have a large project with multiple targets.

Explanation:

• bazel: The Bazel command-line tool.
• build: The command used to build targets.
• //path/to/target: The target you want to build. The target can be specified using its path relative to the workspace root directory. The double slash // indicates the workspace root.

Example Output:

INFO: Analysed target //path/to/target (8 packages loaded, 154 targets configured).
INFO: Found 1 target...
INFO: From Building Bazel Build ...
Starting local Bazel server and connecting to it...
INFO: Building the target //path/to/target:target
INFO: Elapsed time: 10.012s, Critical Path: 9.45s
INFO: 1 process: 1 internal.

2: Cleaning Output Files

To remove the output files generated by Bazel and stop the server if it is running, you can use the bazel clean command.

Code:

bazel clean

Motivation: Cleaning the output files is useful when you want to start fresh and remove all the generated artifacts. It helps to keep the workspace clean and ensures a clean build when executing the next build command.

Explanation:

• bazel: The Bazel command-line tool.
• clean: The command used to remove the output files and clean the workspace.

Example Output:

INFO: All outputs are up to date.

3: Shutting Down Bazel Server

To stop the Bazel server, you can use the bazel shutdown command. This command is useful when there is no ongoing build or when you want to stop the server to perform other tasks.

Code:

bazel shutdown

Motivation: Shutting down the Bazel server is helpful in scenarios where you need to stop the server process safely. It ensures proper cleanup and termination of the server.

Explanation:

• bazel: The Bazel command-line tool.
• shutdown: The command used to stop the Bazel server.

Example Output:

INFO: Server terminated successfully.

4: Displaying Bazel Server Runtime Info

To get information about the runtime details of the Bazel server, you can use the bazel info command. This command provides various details such as the server PID, command line, and platform information.

Code:

bazel info

Motivation: The bazel info command is useful for troubleshooting and obtaining runtime information about the server. It can provide insights into the server configuration, which can help in diagnosing build errors or performance issues.

Explanation:

• bazel: The Bazel command-line tool.
• info: The command used to display runtime information about the Bazel server.

Example Output:

Build label: <build label>
Build target: bazel-out/<architecture>-fastbuild/bin/src/main/java/com/company:target
Build time: <timestamp>
Build user: <username>
Build host: <hostname>

5: Displaying Help

To get help and usage information about the Bazel command-line tool, you can use the bazel help command. This command provides an overview of the available commands and their usage.

Code:

bazel help

Motivation: The bazel help command is useful for quick reference and understanding of the available commands. It provides a brief explanation and usage examples for each command, making it easier for users to learn and utilize Bazel effectively.

Explanation:

• bazel: The Bazel command-line tool.
• help: The command used to display help information.

Example Output:

Usage: bazel <command> <options> ...
Available commands:
  acommand   — A command description
  bcommand   — B command description
  ...
For detailed usage information, run:
  bazel help <command>

6: Displaying Version

To check the version of Bazel installed on your system, you can use the bazel version command. This command provides information about the Bazel version, build label, and build timestamp.

Code:

bazel version

Motivation: Checking the Bazel version is important to ensure that you are using the expected version in your development environment. It helps to identify compatibility issues and ensures that you are utilizing the correct set of features and bug fixes.

Explanation:

• bazel: The Bazel command-line tool.
• version: The command used to display the Bazel version.

Example Output:

Build label: <build label>
Build target: bazel-out/<architecture>-fastbuild/bin/src/main/java/com/company:target
Build time: <timestamp>
Build user: <username>
Build host: <hostname>

These examples illustrate various use cases of the bazel command, covering building targets, cleaning the workspace, shutting down the server, displaying runtime info, getting help, and checking the version. Understanding and utilizing these commands will help developers effectively manage their Bazel projects and optimize their build processes.