package mainimport "fmt"import "os"func main(){ / / `defer`s will _not_ be run when using `os.Exit`,so // this `fmt.Println` will never be called. defer fmt.Println("!") // sometimes ones might use defer to do critical operations // like close a database,remove a lock or free memory // Exit with status code. os.Exit(3)} 0 p& I' M& D& g0 l* O- `