automatically complete the subcommand

[DapengFeng]

When using git, we can press the tab to complete the subcommand. Do you have any ideas about how to implement this function?

[morrisfranken]

Hi @DapengFeng,

Thanks for the feature suggestion! You're correct that command tab-completion is a useful feature for CLI tools.

However, it looks like this functionality is shell-specific, with different implementations required for bash, zsh, fish, powershell, etc. Some command-line parsers typically support this by:

1. Generating completion scripts that users can source in their shell
2. Providing a special command option (like --generate-completion bash) that outputs shell-specific completion rules

For simple cases, you might look into shell-specific solutions like bash's complete command or using tools like argcomplete (Python) as inspiration.