Re: string reading with sscanf

From:

"Daniel T." <daniel_t@earthlink.net>

Newsgroups:

comp.lang.c++

Date:

Mon, 14 Jan 2008 16:39:54 -0500

Message-ID:

<daniel_t-6855F7.16395414012008@earthlink.vsrv-sjc.supernews.net>

"Bint" <bint@csgs.com> wrote:

i have a string "success=1&u=0&name=bint&u=1&name=lucy&u=2&name=barry" etc

i can use sscanf(string,"success=%d", &d) to get the success value. but
after that i just want to read name and u pairs until there are no more. if
Iwere to do a
sscanf (string,"success=%d&u=%d&name=%s"), that would get me the values of
the first u/name, right? is there any way to retrieve the string pointer
position from sscanf so that I can just call it again from that point in the
string?

I would do something like this:

#include <algorithm>
#include <iostream>
#include <iterator>
#include <sstream>
#include <string>

using namespace std;

istream& find( istream& is, char c )
{
   find( istream_iterator<char>( is ), istream_iterator<char>(), c );
   return is;
}

int main()
{
   const char* str =
         "success=1&u=0&name=bint&u=1&name=lucy&u=2&name=barry";

   stringstream ss( str );
   find( ss, '=' );
   int i = 0;
   ss >> i;
   cout << "success = " << i << '\n';
   int u;
   string name;
   while ( find( ss, '=' ) && ss >> u &&
           find( ss, '=' ) && getline( ss, name, '&' ) )
   {
      cout << "u = " << u << " name = " << name << '\n';
   }
}