Guides

Show command usage

Put the -h output of a Go command in a page, so that the page changes when a flag changes.

func main() {
    n := flag.Int("n", 3, "how many lines to print")
    flag.Parse()
    for i := 0; i < *n; i++ {
        fmt.Println(i)
    }
}

# Flags

<!-- docgen:usage cmd=cmd/tool -->
<!-- /docgen:usage -->

# Flags

<!-- docgen:usage cmd=cmd/tool -->
```text
Usage of tool:
  -n int
        how many lines to print (default 3)
```
<!-- /docgen:usage -->

Usage of tool:
  -n int
        how many lines to print (default 3)

The directory is relative to the repository root. A build failure, a crash, or output with no usage is an error.

With args=, docgen runs the command with other arguments, such as args="help config" for a help command. The output must still hold a usage line or a flag line.

For details, see docgen:usage.

Source: docs/guides/usage.md