more good GetAge

src/providers/systemstats.go

@@ -9,6 +9,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 )
 
@@ -236,16 +237,21 @@ func GetShell() string {
 }
 
 func GetAge() string {
-	out, err := exec.Command("stat", "-c", "%W", "/").Output()
+	info, err := os.Stat("/etc/machine-id")
 	if err != nil {
+		info, err = os.Stat("/")
+		if err != nil {
+			return "unknown"
+		}
+	}
+
+	stat, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
 		return "unknown"
 	}
-	birthTime := strings.TrimSpace(string(out))
-	if birthTime == "0" || birthTime == "-" {
-		return "unknown"
-	}
-	age, _ := strconv.Atoi(birthTime)
-	age = int(time.Now().Unix() - int64(age))
-	birth := age / 86400
-	return fmt.Sprintf("%d days", birth)
+
+	birthTime := time.Unix(stat.Ctim.Sec, stat.Ctim.Nsec)
+	days := int(time.Since(birthTime).Hours() / 24)
+
+	return fmt.Sprintf("%d days", days)
 }