Split/parse the query part of a URL. The correct one is getQueryParameters1.

split_query_web.cpp

#include <iostream>
#include <vector>
#include <utility>

std::vector< std::pair<std::string, std::string> > getQueryParameters(std::string query)
{   
    std::vector< std::pair <std::string, std::string> > queryParams;
    size_t pos = 0;
    std::string delimiter = "&";
    std::string token;
    
    while ((pos = query.find(delimiter)) != std::string::npos)
    {
        token = query.substr(0, pos);
                                              
        queryParams.push_back(std::make_pair( token.substr(0, token.find_first_of("=")) ,
                                              token.substr(token.find_first_of("=") + 1, token.length())));

        std::cout << token.substr(0, token.find_first_of("=")) << " " << token.substr(token.find_first_of("=") + 1, token.length()) << std::endl;
    
        query.erase(0, pos + delimiter.length());
    }
    return queryParams;
}

std::vector< std::pair<std::string, std::string> > getQueryParameters1(std::string query)
{   
    std::vector< std::pair <std::string, std::string> > queryParams;
    size_t current;
    size_t next = -1;
    
    do
    {   

        current = next + 1;
        
        next = query.find_first_of("&", current );
        std::string token = query.substr(current, next - current);
                                              
        queryParams.push_back(std::make_pair( token.substr(0, token.find_first_of("=")) ,
                                              token.substr(token.find_first_of("=") + 1, token.length())));
    
        std::cout << token.substr(0, token.find_first_of("=")) << " " << token.substr(token.find_first_of("=") + 1, token.length()) << std::endl;
    }
    while(next != std::string::npos);

    return queryParams;
}

int main(int argc, char *argv[])
{
    std::string s("freq=3939&band=8&serviceid=1101");
    
    //getQueryParameters(s);
    getQueryParameters1(s);

    return 0;
}