diff --git a/main.cpp b/main.cpp
index 3d8918b..0ff7cad 100644
--- a/main.cpp
+++ b/main.cpp
@@ -36,14 +36,18 @@ int main(int argc, char **argv) {
     std::ios::sync_with_stdio();
 
     par.set_program_name("OStask");
+
     par.add<unsigned long>("inquire", 'i', "Inquire the selected process info.",
                            false, ost::PID_MIN, cmdline::range<unsigned long>(ost::PID_MIN, ost::PID_MAX));
-    par.add("help", '?', "show help message.");
-    par.add("all", 'a', "show all info.");
     par.add<unsigned int>("loop", 'l', "loop this program from [1-65535] second.",
                           false, ost::MIN_TIME, cmdline::range(ost::MIN_TIME, ost::MAX_TIME));
     par.add<int>("type", 'y', "Set the show byte type[0=B,1=KB,2=MB,3=GB],Auto decide if not use this.",
                  false, ost::DEFAULT_BTYPE, cmdline::range(0, 3));
+
+    par.add("help", '?', "show help message.");
+    par.add("copyright", 'c', "show copyright and license information.");
+    par.add("all", 'a', "show all info.");
+
     for (auto &&[arg, arf]: ost::funcMap) {
         par.add(arg, arf.shortName, arf.desc);
     }
@@ -51,6 +55,25 @@ int main(int argc, char **argv) {
         std::cout << par.error() << par.usage();
         return 0;
     }
+    if (par.exist("copyright")) {
+        std::cout << "[LICENSE]:\n"
+                     "\n"
+                     "Copyright 2022 Gzh0821/Gaozih\n"
+                     "\n"
+                     "Licensed under the Apache License, Version 2.0 (the \"License\");\n"
+                     "you may not use this file except in compliance with the License.\n"
+                     "You may obtain a copy of the License at\n"
+                     "\n"
+                     "http://www.apache.org/licenses/LICENSE-2.0\n"
+                     "\n"
+                     "Unless required by applicable law or agreed to in writing, software\n"
+                     "distributed under the License is distributed on an \"AS IS\" BASIS,\n"
+                     "WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n"
+                     "See the License for the specific language governing permissions and\n"
+                     "limitations under the License.\n"
+                     "\n";
+        return 0;
+    }
     if (par.exist("type")) {
         int type = par.get<int>("type");
         ost::divByte.first = ost::BTYPE_NAME[type];