feat:add GetExeDllVersion for fileutil,random,package (#257)

* 增加GetExeDllVersion函数获取exe,dll版本号

* 多打文字

* 定位忘记...

* 单独剥离出来一个为windows的,增加RandNumLen为取指定长度随机数.

* ....

* 增加test测试

random/random.go

@@ -327,3 +327,12 @@ func UUIdV4() (string, error) {
 
 	return fmt.Sprintf("%x-%x-%x-%x-%x", uuid[0:4], uuid[4:6], uuid[6:8], uuid[8:10], uuid[10:]), nil
 }
+
+// RandNumLen 生成一个长度为len的随机数
+// Play: https://go.dev/play/p/jpIalcD5rMo
+func RandNumLen(len int) int {
+	m := int(math.Pow10(len) - 1)
+	i := int(math.Pow10(len - 1))
+	ret := rand.Intn(m-i+1) + i
+	return ret
+}

random/random_test.go

@@ -3,6 +3,7 @@ package random
 import (
 	"reflect"
 	"regexp"
+	"strconv"
 	"testing"
 
 	"github.com/duke-git/lancet/v2/internal"
@@ -361,3 +362,9 @@ func TestRandBoolSlice(t *testing.T) {
 		}
 	})
 }
+func TestRandNumLen(t *testing.T) {
+	t.Parallel()
+	randi := RandNumLen(6)
+	assert := internal.NewAssert(t, "TestRandNumLen")
+	assert.Equal(6, len(strconv.Itoa(randi)))
+}