Fix exclude_by_attribute feature on POSIX

The exclude by attribute function is broken on non-Darwin POSIX: linux and freebsd.
This is because those xattrs must be prefixed by a legal namespace. The old xattr
library implicitly appended the user namespace to the xattr, but the current
official go pkg does not (which is just as well).

Also fix the test to remove the discordant old xattr dependency and provide
test cases for both darwin and non-darwin POSIX.

src/duplicacy_entry_test.go

@@ -5,6 +5,8 @@
 package duplicacy
 
 import (
+	"bytes"
+	"encoding/json"
 	"io/ioutil"
 	"math/rand"
 	"os"
@@ -13,11 +15,10 @@ import (
 	"sort"
 	"strings"
 	"testing"
-	"bytes"
-	"encoding/json"
 
-	"github.com/gilbertchen/xattr"
-    "github.com/vmihailenco/msgpack"
+	"github.com/pkg/xattr"
+
+	"github.com/vmihailenco/msgpack"
 )
 
 func TestEntrySort(t *testing.T) {
@@ -175,7 +176,7 @@ func TestEntryOrder(t *testing.T) {
 	directories = append(directories, CreateEntry("", 0, 0, 0))
 
 	entries := make([]*Entry, 0, 4)
-    entryChannel := make(chan *Entry, 1024)
+	entryChannel := make(chan *Entry, 1024)
 	entries = append(entries, CreateEntry("", 0, 0, 0))
 
 	for len(directories) > 0 {
@@ -233,8 +234,16 @@ func TestEntryOrder(t *testing.T) {
 // TestEntryExcludeByAttribute tests the excludeByAttribute parameter to the ListEntries function
 func TestEntryExcludeByAttribute(t *testing.T) {
 
-	if !(runtime.GOOS == "darwin" || runtime.GOOS == "linux") {
-		t.Skip("skipping test not darwin or linux")
+	var excludeAttrName string
+	var excludeAttrValue []byte
+
+	if runtime.GOOS == "darwin" {
+		excludeAttrName = "com.apple.metadata:com_apple_backup_excludeItem"
+		excludeAttrValue = []byte("com.apple.backupd")
+	} else if runtime.GOOS == "linux" || runtime.GOOS == "freebsd" || runtime.GOOS == "netbsd" || runtime.GOOS == "solaris" {
+		excludeAttrName = "user.duplicacy_exclude"
+	} else {
+		t.Skip("skipping test, not darwin, linux, freebsd, netbsd, or solaris")
 	}
 
 	testDir := filepath.Join(os.TempDir(), "duplicacy_test")
@@ -273,7 +282,7 @@ func TestEntryExcludeByAttribute(t *testing.T) {
 	for _, file := range DATA {
 		fullPath := filepath.Join(testDir, file)
 		if strings.Contains(file, "exclude") {
-			xattr.Setxattr(fullPath, "com.apple.metadata:com_apple_backup_excludeItem", []byte("com.apple.backupd"))
+			xattr.Set(fullPath, excludeAttrName, excludeAttrValue)
 		}
 	}
 
@@ -372,4 +381,4 @@ func TestEntryEncoding(t *testing.T) {
 		t.Error("Decoded entry is different than the original one")
 	}
 
-}
+}