0x02 代码
主程序calc.go
package mainimport "os"// 用于获得命令行参数os.Argsimport "fmt"import "simplemath"import "strconv"var Usage = func() { fmt.Println("USAGE: calc command [arguments] ...") fmt.Println("\nThe commands are:\n\tadd\tAddition of two values.\n\tsqrt\tSquare root of a non-negative value.")}func main() { args := os.Args if args == nil || len(args) < 2 { Usage() return } fmt.Println(args[1]) switch args[1] { case "add": if len(args) != 4 { fmt.Println("USAGE: calc add <integer1><integer2>") return } v1, err1 := strconv.Atoi(args[2]) v2, err2 := strconv.Atoi(args[3]) if err1 != nil || err2 != nil { fmt.Println("USAGE: calc add <integer1><integer2>") return } ret := simplemath.Add(v1, v2) fmt.Println("Result: ", ret) case "sqrt": if len(args) != 3 { fmt.Println("USAGE: calc sqrt <integer>") return } v, err := strconv.Atoi(args[2]) if err != nil { fmt.Println("USAGE: calc sqrt <integer>") return } ret := simplemath.Sqrt(v) fmt.Println("Result: ", ret) default:
