SortNames Program

[inbugable]

I was asked to write a sorting program in c++

Specification:
A program to sort a list of names is required.
The file also contains the person’s age and phone number.
The main challenge is that the entire list can not fit into
physical memory at any given time.
There is no limit to the amount of physical disk space.

The Input

An ASCII TSV (Tab Separated values) file containing a list of names.
Each line is of the format:
<Last Name>, <First Name><tab><age><tab><Phone Number><CR>

Sample:

Kalou, Salomon 30 476-2769
Ad****or, Emmanuel 31 310-4951
Morais, Nuno 37 660-6290
Poom, Mart 34 469-8379
Shevchenko, Andriy 26 922-2033
Obi, Mikel 35 888-9370
Ljungberg, Fredrik 34 492-1755
Davenport, Calum 28 240-7734
O'Hara, Jamie 30 333-5168

The Output

A file in the same format sorted by Last Name.

The Program

The final program must take three arguments

Maxnames – the maximum number of names which can be loaded
into memory at any given time
Input - name of the input file
Output – name of the results output file

For example: SortNames.exe 10 input.txt output.txt

So what I manage to achieve so far is to read 10 record from file, sort them and output the result.

CodeListing:

<code>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <algorithm>


using namespace std;

////////////////////////////////////
//Header
////////////////////////////////////
struct PersonInfo
{
string firstName;
string secondName;
int age;
string phoneNumber;

PersonInfo(const string& fName = "",
const string& sName = "",
int personsAge = 0,
const string& number = ""):
firstName(fName), secondName(sName), age(personsAge), phoneNumber(number)
{}

friend bool operator<(const PersonInfo& person1, const PersonInfo& person2);
};

bool operator<(const PersonInfo& person1, const PersonInfo& person2)
{
int c1 = person1.firstName.compare(person2.firstName);
int c2 = person1.secondName.compare(person2.secondName);
int c3 = person1.phoneNumber.compare(person2.phoneNumber);

return (c1 < 0) ||
(c1 == 0 && c2 < 0) ||
(c1 == 0 && c2 == 0 && person1.age < person2.age) ||
(c1 == 0 && c2 == 0 && person1.age == person2.age && c3 < 0);
}

vector<PersonInfo> PersonInfoslist;

void Run(const char* infile, int* maxEntries);
//void WriteToTempFile(const vector<PersonInfo>& p);

////////////////////////////////////
//Source
////////////////////////////////////
void Run(const char* infile,int maxEntries)
{
ifstream inputFile(infile, ios::in);

if (!inputFile)
{
cerr << "Input file "<< infile << " could not be opened!"<<endl;
exit(1);
}

for (int i = 0;i < maxEntries;i++)
{
PersonInfo pInfo;
char* buffer;
inputFile.getline( buffer,2048);
string line = buffer;

int itemNum = 0;
string token;
size_t p0 = 0, p1 = string::npos;

while(p0 != string::npos)
{
p1 = line.find_first_of(",\t ", p0);
if(p1 != p0)
{
token = line.substr(p0, p1 - p0);
}
p0 = line.find_first_not_of(",\t ", p1);

switch( itemNum )
{
case 0:
pInfo.firstName = token;
itemNum++;
break;
case 1:
pInfo.secondName = token;
itemNum++;
break;
case 2:
pInfo.age = atoi(token.c_str());
itemNum++;
break;
case 3:
pInfo.phoneNumber = token;
itemNum=0;
PersonInfoslist.push_back(pInfo);
break;
default:
cout << "Error in tokenizing string!" << endl;
break;
}
}
}

//Sort the items in the vector
sort(PersonInfoslist.begin(), PersonInfoslist.end());

for(vector<PersonInfo>::const_iterator it = PersonInfoslist.begin(); it != PersonInfoslist.end(); ++it)
{
cout << it->firstName << ", " << it->secondName << ", " << it->age << ", " << it->phoneNumber << endl;
}
}

int main(int argc, char** argv)
{
if (argc != 4)
{
cout << "Usage: SortNames <Number of names to read> <Input file> <Output file>" << endl;
exit(1);
}

//Getting the arguments from command line.
int maxEntries = atoi(argv[1]);
const char* inFile = argv[2];
const string outFile = argv[3];

Run(inFile,maxEntries);

return 0;
}
</code>

So I was wondering if a generous C++ programmer out there will be kind enough to help me out on this task. Thanks in advance for any suggestion on improving the current solution