Why does this function always return 0?

I have a function that is always returning 0. The problem I believe is that data is an unsigned char, which is not part of the library. It needs to be unsigned char. So how can I make this work, because what I have doesn't.

#include <string>
#include <iostream>

int Count( const std::string & str, 
           const std::string & obj ) {
    int a = 0;
    int b = 0;
    int c = 0;
    int d = 0;
    std::string ::size_type pos = 0;
    while( (pos = obj.find( str, pos )) 
                 != std::string::npos ) {
        a++;
        b++;
        c++;
        d++;
    pos += str.size();
    }
    return a;
    return b;
    return c;
    return d;
}
void printTcpContent(unsigned char *data,int)
{
    std::string s = (const char*) data;
    int a = Count( "text/html", s );
    int b = Count( "text/plain", s );
    int c = Count( "image/jpg", s );
    int d = Count( "image/png", s );
    std::cout << a << std::endl;
  开发者_StackOverflow中文版  std::cout << b << std::endl;
    std::cout << c << std::endl;
    std::cout << d << std::endl;
}

Try this code instead:

int Count( const std::string & strToFind, 
       const std::string & strToSearch ) {
    int n = 0;
    std::string ::size_type pos = 0;
    while( (pos = strToSearch.find( strToFind, pos )) != std::string::npos ) {
        n++;
        pos += strToSearch.size();
    }
    return n;
}

Also, you can test it works by calling it with smaller test strings, eg Count("3", "1234534")