diff --git a/jni/termExec.cpp b/jni/termExec.cpp
index d7089e11..f8881eda 100644
--- a/jni/termExec.cpp
+++ b/jni/termExec.cpp
@@ -99,7 +99,7 @@ static int throwOutOfMemoryError(JNIEnv *env, const char *message)
     return env->ThrowNew(exClass, message);
 }
 
-static int create_subprocess(const char *cmd, char *const argv[], 
+static int create_subprocess(const int rdt, const char *cmd, char *const argv[], 
     char *const envp[], const char* scripts, int* pProcessId)
 {
     pid_t pid;
@@ -107,7 +107,10 @@ static int create_subprocess(const char *cmd, char *const argv[],
     int pfds2[2];
 
     pipe(pfds);
-    pipe(pfds2);
+
+    if (rdt) {
+      pipe(pfds2);
+    }
 
     pid = fork();
 
@@ -127,9 +130,13 @@ static int create_subprocess(const char *cmd, char *const argv[],
         dup2(pfds[0], 0);
         close(pfds[1]);
 
-        dup2(pfds2[1], 1);
-        dup2(pfds2[1], 2);
-        close(pfds2[0]);
+        if (rdt) {
+          close(1);
+          close(2);
+          dup2(pfds2[1], 1);
+          dup2(pfds2[1], 2);
+          close(pfds2[0]);
+        }
 
         execv(cmd, argv);
 
@@ -144,15 +151,18 @@ static int create_subprocess(const char *cmd, char *const argv[],
         close(pfds[0]);
 
         write(pfds[1], scripts, strlen(scripts)+1);
-
-        close(pfds2[1]);
-        return pfds2[0]; 
+        if (rdt) {
+            close(pfds2[1]);
+            return pfds2[0]; 
+        } else {
+            return -1;
+        }
     }
 }
 
 
 static jobject android_os_Exec_createSubProcess(JNIEnv *env, jobject clazz,
-    jstring cmd, jobjectArray args, jobjectArray envVars, jstring scripts,
+    jint rdt, jstring cmd, jobjectArray args, jobjectArray envVars, jstring scripts,
     jintArray processIdArray)
 {
     const jchar* str = cmd ? env->GetStringCritical(cmd, 0) : 0;
@@ -215,7 +225,7 @@ static jobject android_os_Exec_createSubProcess(JNIEnv *env, jobject clazz,
     }
 
     int procId;
-    int ptm = create_subprocess(cmd_8.string(), argv, envp, scripts_8.string(), 
+    int ptm = create_subprocess(rdt, cmd_8.string(), argv, envp, scripts_8.string(), 
         &procId);
 
     if (argv) {
@@ -324,7 +334,7 @@ static int register_FileDescriptor(JNIEnv *env)
 static const char *classPathName = "com/github/shadowsocks/Exec";
 
 static JNINativeMethod method_table[] = {
-    { "createSubprocess", "(Ljava/lang/String;[Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;[I)Ljava/io/FileDescriptor;",
+    { "createSubprocess", "(ILjava/lang/String;[Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;[I)Ljava/io/FileDescriptor;",
         (void*) android_os_Exec_createSubProcess },
     { "waitFor", "(I)I",
         (void*) android_os_Exec_waitFor},
diff --git a/libs/armeabi/libexec.so b/libs/armeabi/libexec.so
index a9659fc7..54d9372b 100755
Binary files a/libs/armeabi/libexec.so and b/libs/armeabi/libexec.so differ
diff --git a/src/com/github/shadowsocks/Exec.java b/src/com/github/shadowsocks/Exec.java
index edc892bd..0c6009dc 100755
--- a/src/com/github/shadowsocks/Exec.java
+++ b/src/com/github/shadowsocks/Exec.java
@@ -43,6 +43,7 @@ public class Exec {
      * Callers are responsible for calling Exec.close() on the returned file
      * descriptor.
      *
+     * @param rdt       Whether redirect stdout and stderr
      * @param cmd       The command to execute.
      * @param args      An array of arguments to the command.
      * @param envVars   An array of strings of the form "VAR=value" to be added to the
@@ -52,7 +53,7 @@ public class Exec {
      *                  process will be written.
      * @return          File descriptor
      */
-    public static native FileDescriptor createSubprocess(String cmd,
+    public static native FileDescriptor createSubprocess(int rdt, String cmd,
                                                          String[] args, String[] envVars,
                                                          String scripts, int[] processId);
 
diff --git a/src/com/github/shadowsocks/Utils.java b/src/com/github/shadowsocks/Utils.java
index 8fcc11d7..64356b0b 100755
--- a/src/com/github/shadowsocks/Utils.java
+++ b/src/com/github/shadowsocks/Utils.java
@@ -44,7 +44,7 @@ public class Utils {
             String arg0 = argList.get(0);
             String[] args = argList.toArray(new String[1]);
 
-            return Exec.createSubprocess(arg0, args, null,
+            return Exec.createSubprocess(result != null ? 1 : 0, arg0, args, null,
                     scripts + "\nexit\n", processId);
         }
 
@@ -112,7 +112,7 @@ public class Utils {
                     pipe = createSubprocess(pid, getShell());
                 }
 
-                if (pipe == null) return;
+                if (result == null || pipe == null) return;
 
                 if (pid[0] != -1) {
                     exitcode = Exec.waitFor(pid[0]);
@@ -125,8 +125,7 @@ public class Utils {
                 // Read stdout
                 while (stdout.available() > 0) {
                     read = stdout.read(buf);
-                    if (result != null)
-                        result.append(new String(buf, 0, read));
+                    result.append(new String(buf, 0, read));
                 }
 
             } catch (Exception ex) {