Question 1

How do I add shell completion to my Clamp app?

Accepted Answer

Require 'clamp/completion' in your script, then use the hidden --shell-completions option to generate scripts for bash, zsh, or fish. For example, add eval "$(myapp --shell-completions bash)" to your .bashrc to activate it.

Question 2

Can Clamp use environment variables for option defaults?

Accepted Answer

Yes, specify the environment_variable parameter when declaring an option, and Clamp will check that variable if no command-line value is provided, before falling back to a default.

Question 3

Clamp vs Thor for Ruby CLI tools: which should I use?

Accepted Answer

Clamp is more minimal and focused on argument parsing with a clean DSL, ideal for quick, structured CLI apps. Thor offers more features like generators and a larger ecosystem, better for complex projects needing extra tooling.

Question 4

How to handle validation across multiple options in Clamp?

Accepted Answer

Perform complex validation in the #execute method and use signal_usage_error for custom messages, as Clamp's validation blocks are per-option and don't support cross-option checks directly.

Question 5

Is Clamp good for internationalizing help text?

Accepted Answer

Yes, Clamp provides localization support via the Clamp.messages hash, allowing you to override strings with custom translations using libraries like Gettext for tailored help output.

Question 6

How do I set a default subcommand in Clamp?

Accepted Answer

Assign self.default_subcommand = 'name' in your command class, and Clamp will automatically select that subcommand when no subcommand argument is provided on the command line.

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