How to Use the Command 'hg' in Mercurial (with examples)

Mercurial, often referred to by its command hg, is a distributed source control management system. It is designed for handling projects of any size and offers high performance, scalability, and flexibility. Mercurial enables developers and teams to effectively manage their codebase with its robust set of features. The hg command is the entry point for initiating various actions within the Mercurial environment, allowing users to perform a wide array of tasks related to source code management.

Execute a Mercurial Command

Code:

hg command

Motivation:

Executing a Mercurial command is fundamental when interacting with a Mercurial repository. Whether you are committing changes, pulling new updates, or creating branches, the ability to specify and run the right command is critical for efficient version control. For developers working on collaborative projects, executing commands correctly ensures seamless integration of changes and minimizes conflicts between different contributors’ code.

Explanation:

• hg: This is the command line interface for Mercurial. It’s the prefix used to denote an operation or action within the Mercurial environment.
• command: This represents a placeholder for any specific Mercurial action or subcommand you intend to execute, such as commit, pull, merge, etc.

Example Output:

While the output varies greatly depending on the specified command, executing hg status might return:

M file1.txt
A file2.txt
? file3.txt

This indicates that file1.txt has modifications, file2.txt is newly added to the repository, and file3.txt is an untracked file.

Display Help

Code:

hg help

Motivation:

Navigating the numerous features and subcommands available in Mercurial can be overwhelming, especially for new users. Displaying help provides a quick reference or overview of the available commands. This functionality aids in understanding how to utilize all of Mercurial’s capabilities by providing descriptions and usage instructions for each command.

Explanation:

• hg: The command line utility for Mercurial operations.
• help: The specific command used to access the help documentation, which lists all commands and their brief descriptions.

Example Output:

Mercurial Distributed SCM

basic commands:

 add
 annotate
 archive
 branches
 ...

This output lists diverse commands available within Mercurial, along with a brief description, offering an overview of its core functionalities.

Display Help for a Specific Command

Code:

hg help command

Motivation:

For developers requiring in-depth details about a particular operation, such as syntax, options, and examples, accessing help for a specific command is invaluable. Whether you’re learning a new command or recalling its options, command-specific help reduces the learning curve and enhances productivity by providing targeted information.

Explanation:

• hg: The base command for interacting with Mercurial.
• help: The subcommand used to invoke the help system within Mercurial.
• command: A placeholder for the specific command (like commit, update, etc.) you want detailed information about.

Example Output:

If you run hg help commit, you might see:

hg commit [OPTION]... [FILE]...

aliases: ci

record changes to the repository
...

It shows the syntax for commit, possible options, and a description, facilitating a deeper understanding of how to use this command.

Check the Mercurial Version

Code:

hg --version

Motivation:

Checking the Mercurial version is crucial for ensuring compatibility between team members and tools. Different features or bug fixes may be present in various versions, influencing how certain commands behave. This is especially significant when integrating with third-party tools or plugins that may require specific Mercurial versions.

Explanation:

• hg: The command line interaction method for Mercurial.
• --version: An option used to display the version information of the installed Mercurial client.

Example Output:

Mercurial Distributed SCM (version 5.9.1)
(see https://mercurial-scm.org for more information)

This output clearly indicates the version of Mercurial currently installed, allowing developers to verify their environment setup and plan upgrades if necessary.

Conclusion:

Understanding the fundamental hg command in Mercurial is essential for anyone involved in software development and version control. Whether it’s executing commands, seeking help, or checking version compatibility, these use cases illustrate the pivotal role of hg in managing and maintaining source code efficiently. Mastering these basic operations can significantly streamline workflows, foster collaboration, and enhance productivity across development teams.