Go - Building CLI tools with goopts, a command-line argument parsing library

Tue, 20 May 2025 10:00:00 +0000

When I started building security tools in Go for The Manticore Project, I quickly ran into a recurring problem. Every tool needed argument parsing: authentication flags, LDAP connection settings, debug options, positional arguments for modes and subcommands. Go’s standard flag package handles simple cases, but it does not support argument groups, subcommands, mutually exclusive options, or even required arguments.

I looked at existing libraries. Some were too minimal, others tried to do too much and imposed heavy conventions on how you structure your code. None of them felt right for the kind of tools I was building: security tools with multiple modes (like audit, add, remove), each with their own set of arguments, and common argument groups for authentication and LDAP settings.

Cli on The Manticore Project

Go - Building CLI tools with goopts, a command-line argument parsing library