argparse-c

Build C99 command-line tools with a Python argparse-style authoring experience.

argparse-c is for developers who want more than basic flag parsing: completion, manpage generation, subcommands, nargs, and known-args parsing are all available from the same parser definition.

Why start here?

Use this site when you want to:

• install the library from source or release assets
• copy a minimal CLI example and then expand it
• add completion or manpage generation without inventing custom plumbing
• look up the exact API contract after learning the basics

Recommended reading order

1. Getting Started — install the library, run the first sample, and learn the minimum parser flow
2. AI agent guide — ownership, cleanup order, and wrapper-CLI parsing policy
3. Guides — dive into features as you need them
4. Basic usage
5. Options and types
6. nargs
7. Subcommands
8. Completion callbacks
9. known args / unknown args
10. fromfile_prefix_chars
11. Reference
12. API Reference (English)
13. FAQ

What you can build quickly

• a single-command CLI with required flags and positional inputs
• a nested subcommand CLI
• a wrapper command that forwards unknown arguments via ap_parse_known_args(...)
• a CLI that emits bash/fish completion scripts and a manpage

Example programs in this repository

• sample/example1.c — minimal parse/validate/read flow
• sample/example_completion.c — completion and manpage generator entrypoints
• sample/example_subcommands.c — nested subcommands and subcommand_path

Need Japanese docs?

• 日本語トップ
• 日本語 Getting Started