go-cli-tools

# Go CLI Tools Skill

Build professional command-line applications with Go.

## Overview

Complete guide for building CLI tools with Cobra, Viper configuration, terminal UI, and cross-platform support.

## Parameters

| Parameter | Type | Required | Default | Description |
|-----------|------|----------|---------|-------------|
| framework | string | no | "cobra" | CLI framework |
| config_format | string | no | "yaml" | Config: "yaml", "json", "toml" |
| interactive | bool | no | false | Include interactive prompts |

## Core Topics

### Cobra Setup
```go
var rootCmd = &cobra.Command{
    Use:     "myapp",
    Short:   "My CLI application",
    Version: version,
    PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
        return initConfig()
    },
}

func Execute() int {
    if err := rootCmd.Execute(); err != nil {
        fmt.Fprintln(os.Stderr, err)
        return 1
    }
    return 0
}

func init() {
    rootCmd.PersistentFlags().StringVarP(&cfgFile, "config", "c", "", "config file")
    rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "verbose output")
}
```

### Subcommands
```go
var serveCmd = &cobra.Command{
    Use:   "serve",
    Short: "Start the server",
    RunE: func(cmd *cobra.Command, args []string) error {
        port, _ := cmd.Flags().GetInt("port")
        return runServer(port)
    },
}

func init() {
    serveCmd.Flags().IntP("port", "p", 8080, "server port")
    rootCmd.AddCommand(serveCmd)
}
```

### Viper Configuration
```go
func initConfig() error {
    if cfgFile != "" {
        viper.SetConfigFile(cfgFile)
    } else {
        home, _ := os.UserHomeDir()
        viper.AddConfigPath(home)
        viper.AddConfigPath(".")
        viper.SetConfigName(".myapp")
        viper.SetConfigType("yaml")
    }

    viper.SetEnvPrefix("MYAPP")
    viper.AutomaticEnv()
    viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))

    if err := viper.ReadInConfig(); err != nil {
        if _, ok := err.(viper.ConfigF