_INSIDE THE SYSTEM<TOOL> LIBRARY_
by Michael J. Vilot

Listing One
rionb04p30.unisys.com.br - - [22/Mar/1996:18:12:46 -0500] "GET 
/ooad.html HTTP/1.0" 200 2006 "http://www.objects.destek.com/" 
"Mozilla/1.22 (Windows; I; 16bit)"

Listing Two 
#include <fstream.h>
#include <iomanip.h>

#include <ospace/string.h>  // should be <string>
#include <map.h>            // for map<>, pair<>, make_pair()
#include <set.h>

typedef pair<string, string> Pairtype;
typedef set<string, less<string> > Settype;
typedef map<string, Settype, less<string> > Maptype;

static Maptype m;   // shared by input() and output()

static Pairtype parse(istream& file, unsigned long& line);
static string empty;    // returned as "browser" @ eof

unsigned long input(istream& file) throw(unsigned long)
{
  unsigned long line = 1;
  while (file && !file.eof()) {
    Pairtype p = parse(file,line);
    string& browser = p.first;
    string& site    = p.second;

    if (browser != empty) {
      Settype& set = m[browser];
      set.insert(site);
    }
  }
  if ( !file.eof() ) throw line;
  return line;
}
static void quoted_string(istream&, unsigned long);
static char buffer[512];  // shared
static Pairtype parse(istream& file, unsigned long& line)
{
  string site;
  file >> site; // 1st field
  if (file.eof()) return make_pair(empty,site);
// ignore through date (4th field)
  file.getline(buffer, sizeof buffer, ']');
// ignore command (5th field)
  quoted_string(file, line);
  // ignore 6th & 7th fields
  int n1;

  file >> n1 >> buffer;
// ignore referrer URL (8th field)
  quoted_string(file, line);
  // get browser info (9th/last field)
  file.getline(buffer, sizeof buffer);  ++line;

  string browser(buffer);
  return make_pair(browser, site);
}
static void quoted_string(istream& file, unsigned long line)
{
  char x = ' ';
  file >> ws; // skip whitespace
  file.get(x);  if (x != '"') throw line;
  file.get(buffer, sizeof buffer, '"');
  file.get(x);  if (x != '"') throw line;
}
void output(ostream& out)
{
  out << "Browsers (and their sites): " << endl;
  out.flags( out.flags() | ios::left );
  Maptype::iterator it;
  for (it = m.begin(); it != m.end(); ++it) {
    out << (*it).first << endl;
    Settype& set = (*it).second;
    Settype::iterator i2;
    for (i2 = set.begin(); i2 != set.end(); ++i2) {
      out << '\t' << *i2 << endl;
    }
  }
}

Listing Three
"Infoseek Robot 1.17"
        homer-bbn.infoseek.com
        homer.infoseek.com
"Lycos Spider (Rex)/TEST v1.0 libwww/3.1"
        fourteen.srv.lycos.com
        qe20.lycos.com
"Mozilla/1.1 (Windows; U; 32bit)"
        mail.jabil.com
"Mozilla/1.1N (Macintosh; I; PPC)"
        box772.labs.cis.pitt.edu
        gate.cs.auckland.ac.nz
 ...
"Mozilla/2.01 (X11; I; OSF1 V3.2 alpha)"
        picasso.idt-isep.ipp.pt
"Mozilla/2.0GoldB1 (Win95; I)"
        206.15.181.148
        ad05-103.compuserve.com
        barredu207.k12.vt.us
        dd35-188.compuserve.com
        fairisaac.com

        hd63-109.compuserve.com
 ...

Listing Four
(Connect to site on "well known" port # 119, using TCP/IP)
200 quartz.mv.com NNTP[auth] server version 1.5.12.1 ready (posting ok).
list active
215 Newsgroups in form "group high low flags".
 ...
 .  (final output line)
 quit

Listing Five
#include <deque.h>
#include <queue.h>          // for priority_queue
#include <ospace/string.h>  // should be simply <string>

#include <ospace/socket.h>
#include <ospace/stream/tstream.h>
#include <ospace/event/event.h> // for os_event

typedef priority_queue< deque< string >, greater< string > > Qtype;

static void open(iostream&) throw(const char*);
static void input(iostream&, Qtype&);
static void output(Qtype&);

int main(int argc, char *argv[])  // list active newsgroups
{
  try {
  // Attach a socket to the NNTP server (well-known port #119)
    const char* name = (argc != 2) ? "news.mv.com" : argv[1];
    os_socket_address nntp_server( os_ip_address(name), 119 );

  // Create an input stream attached to the socket
    os_tcp_socket socket;
    socket.connect_to( nntp_server );
    os_tstream stream( socket );
    open(stream);   // Check login, send list command
  
  // Create a priority_queue to sort the names
    Qtype queue;
    input(stream, queue);   // Gather names
    stream << "quit" << endl;   // Close connection
    output(queue);  // Display the results

  } catch(os_event& ev) {
    cerr << "ObjectSpace exception: " << ev << endl;
    return 1;
  } catch(const char* msg) {
    cerr << "NNTP Server Error: " << msg << endl;
    return 1;
  }

  return 0;
}
static void open(iostream& stream) throw(const char*)
{
  // Read login information
  static char buffer[256];
  stream.getline( buffer, sizeof buffer );
  if ( buffer[0] != '2' ) throw "NNTP not found on port";

  // Send request to list active newsgroups
  stream << "list active" << endl;

  // Check status (200+)
  stream.getline( buffer, sizeof buffer );
  if ( buffer[0] != '2' ) throw "list command failed";
}
static void input(iostream& stream, Qtype& q)
{
  unsigned long count = 0;
  while ( !stream.eof() ) {
    string s;
    stream >> s;  // read 1st string (newsgroup)

    // Check for end of listing
    if (s[0] == '.') break;

    q.push(s);  // save the result

    // Skip past remainder of line
    static char buffer[256];
    stream.getline( buffer, sizeof buffer );

    // Note progress
    ++count;
    if ( (count % 100) == 0 ) cout << "Read " << count << " so far." << endl;
  }
}
static void output(Qtype& q)
{
  cout << "========== " << q.size() << " ACTIVE NEWSGROUPS ==========" << endl;
  while (q.size()) {
    cout << q.top() << endl;
    q.pop();
  }
  cout << "=============================================" << endl;
}

Listing Six
(connect_to news.mv.com)
Read 100 so far.
 ...
Read 7300 so far.

Send:  quit
========== 7394 ACTIVE NEWSGROUPS ==========
alt.0d
alt.1d
alt.2600
alt.2600.hope.announce
alt.2600.hope.d
alt.2600.hope.tech
alt.2600hz
alt.3d
 ...
t.unix
vt.uucp
vt.vtuug
wash.general
wash.politics
wash.test
wi.forsale
wpi.clubs.hsa