normalized env variable names for bash

common/platform/platform.go

@@ -0,0 +1,42 @@
+package platform
+
+import (
+	"os"
+	"strconv"
+	"strings"
+)
+
+type EnvFlag struct {
+	Name    string
+	AltName string
+}
+
+func (f EnvFlag) GetValue(defaultValue string) string {
+	if v, found := os.LookupEnv(f.Name); found {
+		return v
+	}
+	if len(f.AltName) > 0 {
+		if v, found := os.LookupEnv(f.AltName); found {
+			return v
+		}
+	}
+
+	return defaultValue
+}
+
+func (f EnvFlag) GetValueAsInt(defaultValue int) int {
+	const PlaceHolder = "xxxxxx"
+	s := f.GetValue(PlaceHolder)
+	if s == PlaceHolder {
+		return defaultValue
+	}
+	v, err := strconv.ParseInt(s, 10, 32)
+	if err != nil {
+		return defaultValue
+	}
+	return int(v)
+}
+
+func NormalizeEnvName(name string) string {
+	return strings.Replace(strings.ToUpper(strings.TrimSpace(name)), ".", "_", -1)
+}

common/platform/platform_test.go

@@ -0,0 +1,41 @@
+package platform_test
+
+import (
+	"testing"
+
+	. "v2ray.com/core/common/platform"
+	"v2ray.com/core/testing/assert"
+)
+
+func TestNormalizeEnvName(t *testing.T) {
+	assert := assert.On(t)
+
+	cases := []struct {
+		input  string
+		output string
+	}{
+		{
+			input:  "a",
+			output: "A",
+		},
+		{
+			input:  "a.a",
+			output: "A_A",
+		},
+		{
+			input:  "A.A.B",
+			output: "A_A_B",
+		},
+	}
+	for _, test := range cases {
+		assert.String(NormalizeEnvName(test.input)).Equals(test.output)
+	}
+}
+
+func TestEnvFlag(t *testing.T) {
+	assert := assert.On(t)
+
+	assert.Int(EnvFlag{
+		Name: "xxxxx.y",
+	}.GetValueAsInt(10)).Equals(10)
+}