C++: CGI GET Request

GET request is easy to process, as Query String is passed in environment variable.
Follow is the code to process GET Request:

void ProcessQueryString(map<string,string>& query) {
    char *queryStr = getenv("QUERY_STRING");

    char *ptr=NULL;
    char *savPtr;
    ptr=strtok_r(queryStr, "&=", &savPtr);
    while (ptr != NULL) {
        string key(ptr);
        ptr = strtok_r(NULL, "&=", &savPtr);
        if(ptr!=NULL && strlen(ptr) > 0) {
            string value(ptr);
            query[key]=value;
        }
        ptr=strtok_r(NULL, "&=", &savPtr);

    }
}