``` package main import ( "flag" "fmt" ) func main() { backup_dir := flag.String("b", "/home/default_dir", "backup path") debug_mode := flag.Bool("d", false, "debug mode") flag.Parse() fmt.Println("backup_dir: ", *backup_dir) fmt.Println("debug_mode: ", *debug_mode) } ``` /** 启动命令：go run main.go -b /home/backup 输出结果： backup_dir: /home/backup // 因为指定了路径，所以覆盖了默认路径 debug_mode: false // 启动命令里不带 -d 参数，所以启用默认值 */ 查看命令参数-help ``` go run main.go -help ``` 输出结果如下 > Usage of C:\Users\ADMINI~1\AppData\Local\Temp\go-build1491072069\b001\exe\demo.exe: > -b string > backup path (default "/home/default_dir") > -d debug mode