diff --git a/cmake/Common.cmake b/cmake/Common.cmake
index 2f65ba5..743a099 100755
--- a/cmake/Common.cmake
+++ b/cmake/Common.cmake
@@ -29,15 +29,11 @@ endif()
 
 #-------------------------------------------------------------
 
-if("${INSTALL_PREFIX}" STREQUAL "")
-    IF (UNIX)
-        set(INSTALL_PREFIX "/usr/local/tars/cpp")
-    ELSE()
-        set(INSTALL_PREFIX "c:\\tars\\cpp")
-    ENDIF()
-
-    set(CMAKE_INSTALL_PREFIX ${INSTALL_PREFIX})
-endif()
+IF (UNIX)
+    set(CMAKE_INSTALL_PREFIX "/usr/local/tars/cpp" CACHE STRING "set install path" FORCE)
+ELSE()
+    set(CMAKE_INSTALL_PREFIX "c:\\tars\\cpp" CACHE STRING "set install path" FORCE)
+ENDIF()
 
 #-------------------------------------------------------------
 IF (APPLE)
@@ -89,7 +85,7 @@ message("CMAKE_BINARY_DIR:          ${CMAKE_BINARY_DIR}")
 message("PROJECT_SOURCE_DIR:        ${PROJECT_SOURCE_DIR}")
 message("CMAKE_BUILD_TYPE:          ${CMAKE_BUILD_TYPE}")
 message("PLATFORM:                  ${PLATFORM}")
-message("INSTALL_PREFIX:            ${INSTALL_PREFIX}")
+message("CMAKE_INSTALL_PREFIX:      ${CMAKE_INSTALL_PREFIX}")
 message("BIN:                       ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}") 
 message("TARS2CPP:                  ${TARS2CPP}") 
 #-------------------------------------------------------------
diff --git a/servant/CMakeLists.txt b/servant/CMakeLists.txt
index d305802..a2ee3d4 100644
--- a/servant/CMakeLists.txt
+++ b/servant/CMakeLists.txt
@@ -37,7 +37,7 @@ macro(complice_tars OUT_DEPENDS_LIST HEADER TARS_DIR)
         add_custom_command(
                 OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/${TARS_H}
                 WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-                DEPENDS tars2cpp ${TARS_IN}
+                DEPENDS tars2cpp ${FILE}
                 COMMAND ${TARS2CPP} --with-tars ${INCLUDE} ${TARS_IN}
                 COMMENT "${TARS2CPP} --with-tars ${INCLUDE} ${TARS_IN}")
 
diff --git a/servant/protocol b/servant/protocol
index ed2cb05..8d1993b 160000
--- a/servant/protocol
+++ b/servant/protocol
@@ -1 +1 @@
-Subproject commit ed2cb055d5799d45bdeeec920092ee3fccd85e2b
+Subproject commit 8d1993be26db9792f581e779890fb83fec0b9de4
diff --git a/util/include/util/tc_port.h b/util/include/util/tc_port.h
index ddfc481..2dd7785 100755
--- a/util/include/util/tc_port.h
+++ b/util/include/util/tc_port.h
@@ -66,6 +66,8 @@ public:
     static std::string getEnv(const std::string &name);
 
     static void setEnv(const std::string &name, const std::string &value);
+
+    static std::string exec(const char* cmd);
 };
 
 }
diff --git a/util/src/tc_port.cpp b/util/src/tc_port.cpp
index 2473ca6..e43abfa 100755
--- a/util/src/tc_port.cpp
+++ b/util/src/tc_port.cpp
@@ -189,4 +189,28 @@ void TC_Port::setEnv(const string &name, const string &value)
 	setenv(name.c_str(), value.c_str(), true);
 #endif
 }
-}
\ No newline at end of file
+
+string TC_Port::exec(const char *cmd)
+{
+	string fileData;
+#if TARGET_PLATFORM_WINDOWS
+    FILE* fp = _popen(cmd, "r");
+#else
+    FILE* fp = popen(cmd, "r");
+#endif
+    static size_t buf_len = 2 * 1024 * 1024;
+    char *buf = new char[buf_len];
+    memset(buf, 0, buf_len);
+    fread(buf, sizeof(char), buf_len - 1, fp);
+#if TARGET_PLATFORM_WINDOWS
+    _pclose(fp);
+#else
+    pclose(fp);
+#endif
+    fileData = string(buf);
+    delete []buf;
+
+	return fileData;
+}
+
+}