Welcome to urfave/cli-altsrc/v3

urfave/cli-altsrc/v3 is an extended value source integration library for urfave/cli/v3 with support for JSON, YAML, and TOML. The primary reason for this to be a separate library is that third-party libraries are used for these features which are otherwise not used throughout urfave/cli/v3.

Example

configFiles := []string{
	filepath.Join(testdataDir, "config.yaml"),
	filepath.Join(testdataDir, "alt-config.yaml"),
}

app := &cli.Command{
	Name: "greet",
	Flags: []cli.Flag{
		&cli.StringFlag{
			Name:    "name",
			Aliases: []string{"n"},
			Sources: altsrc.YAML("greet.name", configFiles...),
		},
		&cli.IntFlag{
			Name:    "enthusiasm",
			Aliases: []string{"!"},
			Sources: altsrc.YAML("greet.enthusiasm", configFiles...),
		},
	},
	Action: func(cCtx *cli.Context) error {
		punct := ""
		if cCtx.Int("enthusiasm") > 9000 {
			punct = "!"
		}

		fmt.Fprintf(os.Stdout, "Hello, %[1]v%[2]v\n", cCtx.String("name"), punct)

		return nil
	},
}

// Simulating os.Args
os.Args = []string{"greet"}

if err := app.Run(context.Background(), os.Args); err != nil {
	fmt.Fprintf(os.Stdout, "OH NO: %[1]v\n", err)
}