#42: Add Rand func to generate a pseudo-random integer between min an…

…d max based on unix-nano time seed

.gitattributes

@@ -0,0 +1,5 @@
+/.github export-ignore
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/CODE_OF_CONDUCT.md export-ignore
+/CONTRIBUTING.md export-ignore

README.md

@@ -36,6 +36,8 @@ Go library for PHP community with convenient functions
 * [Network](#user-content-network)
     * [IP2Long/Long2Ip](#user-content-ip2longlong2ip)
     * [GetMxrr](#user-content-getmxrr)
+* [Math](#user-content-math)
+    * [Rand](#user-content-rand)    
 
 #### Installation 
 
@@ -310,3 +312,10 @@ ip := pgo.Long2ip(2956665461) // "176.59.34.117"
 ```go
 isMx, mxs, _ := pgo.GetMxrr("google.com") // e.g.: true, n
 ```
+
+### Math
+
+#### Rand
+```go
+rand := pgo.Rand(1, 100)
+```

go.mod

@@ -2,4 +2,7 @@ module pgo
 
 go 1.13
 
-require github.com/stretchr/testify v1.4.0
+require (
+	github.com/djherbis/atime v1.0.0
+	github.com/stretchr/testify v1.4.0
+)

math.go

@@ -0,0 +1,13 @@
+package pgo
+
+import (
+	"math/rand"
+	"time"
+)
+
+// Rand returns a pseudo-random integer between min and max based on unix-nano time seed
+// !! for random numbers suitable for security-sensitive work, use the crypto/rand package instead
+func Rand(min, max int64) int64 {
+	rand.Seed(time.Now().UnixNano())
+	return rand.Int63n(max - min + 1) + min
+}

math_test.go

@@ -0,0 +1,13 @@
+package pgo_test
+
+import (
+	"github.com/stretchr/testify/assert"
+	"pgo"
+	"testing"
+)
+
+func TestRand(t *testing.T) {
+	r1 := pgo.Rand(1, 100)
+	assert.GreaterOrEqual(t, r1, int64(1))
+	assert.LessOrEqual(t, r1, int64(100))
+}