diff --git a/CMakeLists.txt b/CMakeLists.txt
index ea408b7..30b5790 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,7 +22,6 @@ set(EXECUTABLE_OUTPUT_PATH ${CMAKE_SOURCE_DIR}/build/bin)
 set(LIBRARY_OUTPUT_PATH ${CMAKE_SOURCE_DIR}/lib)
 
 
-
 find_package(gflags REQUIRED)
 
 include_directories(lz4/lib)
diff --git a/README.org b/README.org
index f185944..5408b11 100644
--- a/README.org
+++ b/README.org
@@ -1,3 +1,8 @@
+
+* Introduction
+
+  A collection of C++
+
 * install
 
 git clone --recursive git@github.com:zzjjzzgggg/cpplib.git
diff --git a/io/ioutils.h b/io/ioutils.h
index 2a4e6fb..8b4d597 100644
--- a/io/ioutils.h
+++ b/io/ioutils.h
@@ -28,18 +28,26 @@ std::unique_ptr<IOIn> getIOIn(const std::string& filename);
 
 class TSVParser {
 private:
-    size_t line_NO_;
     char split_ch_;
-    char buf_[1024];  // assume each line has a maximum length of 1024 bytes.
+    size_t line_NO_;
+    std::string filename_;
+
+    // assume each line has a maximum length of 1024 bytes.
+    char buf_[1024];
     std::vector<std::string> field_vec_;
     std::unique_ptr<IOIn> in_ptr_;
 
 public:
     TSVParser(const std::string& filename, const char sep = '\t')
-        : line_NO_(0), split_ch_(sep) {
+        : split_ch_(sep), line_NO_(0), filename_(filename) {
         in_ptr_ = getIOIn(filename);
     }
 
+    void reset() {
+        line_NO_ = 0;
+        in_ptr_ = getIOIn(filename_);
+    }
+
     bool next();
 
     int getNumFields() const { return (int)(field_vec_.size()); }
diff --git a/io/lz4io.h b/io/lz4io.h
index ec7f8aa..f84be63 100644
--- a/io/lz4io.h
+++ b/io/lz4io.h
@@ -165,6 +165,6 @@ class LZ4In : public IOIn {
 
     void decompress(const char* output_file_name);
 };
-}
+}  // namespace ioutils
 
 #endif /* __LZ4IO_H__ */
diff --git a/test/test_ioutils.cpp b/test/test_ioutils.cpp
index cf5c055..4df8360 100644
--- a/test/test_ioutils.cpp
+++ b/test/test_ioutils.cpp
@@ -6,8 +6,8 @@
  */
 
 #include <cstdio>
-#include "ioutils.h"
-#include "osutils.h"
+#include "../io/ioutils.h"
+#include "../os/osutils.h"
 
 void test_null_ptr() {
     // auto ptr = std::unique_ptr<ioutils::IOIn>();
@@ -27,7 +27,19 @@ void test_print() {
     ioutils::printMap<int, int>(m);
 }
 
+void test_tsvparser() {
+    printf("use file test.dat\n");
+    ioutils::TSVParser ss("test.dat");
+    while (ss.next()) printf("%d ", ss.get<int>(0));
+    printf("\n");
+
+    ss.reset();
+    while (ss.next()) printf("%d ", ss.get<int>(0));
+    printf("\n");
+}
+
 int main(int argc, char* argv[]) {
-    test_null_ptr();
+    // test_null_ptr();
+    test_tsvparser();
     return 0;
 }