Add function to extract stk version and OS from user agent

src/utils/string_utils.cpp

@@ -1377,6 +1377,23 @@ namespace StringUtils
         assert(versionToInt("1.0-rc1"         ) ==  10000021);   // same as 1-rc1
     }   // unitTesting
     // ------------------------------------------------------------------------
+    std::pair<std::string, std::string> extractVersionOS(
+                                                 const std::string& user_agent)
+    {
+        std::pair<std::string, std::string> ret;
+        // '#^(SuperTuxKart/[a-z0-9\\.\\-_]+)( \\(.*\\))?$#'
+        std::vector<std::string> out = split(user_agent, '/');
+        if (out.size() != 2 || out[1].empty() || out[1].back() != ')')
+            return ret;
+        std::vector<std::string> out2 = split(out[1], '(');
+        if (out2.size() != 2 || out2[0].empty() || out2[0].back() != ' ' ||
+            out2[1].size() < 2)
+            return ret;
+        ret.first = out2[0].substr(0, out2[0].size() - 1);
+        ret.second = out2[1].substr(0, out2[1].size() - 1);
+        return ret;
+    }   // extractVersionOS
+    // ------------------------------------------------------------------------
     std::string getUserAgentString()
     {
         std::string uagent(std::string("SuperTuxKart/") + STK_VERSION);

src/utils/string_utils.hpp

@@ -300,6 +300,9 @@ namespace StringUtils
      */
     std::string getHostNameFromURL(const std::string& url);
     // ------------------------------------------------------------------------
+    std::pair<std::string, std::string> extractVersionOS(
+                                                const std::string& user_agent);
+    // ------------------------------------------------------------------------
     /* Get line from istream with taking into account for its line ending. */
     inline std::istream& safeGetline(std::istream& is, std::string& t)
     {