Thread: File I/O Sorting Months

Try:

Code:

if (!date01.is_open())
    date01.open("January.all");
date01<<s2Line<<endl;

Let's look at a sample from your posted code and examine why this is happening:

Code:

ofstream date01;

...

if ("01" ==s2Line.substr(535,2))
{
    if (!date01)
        ofstream date01("January.all");
    date01<<s2Line<<endl;
    g++;
}

The line in red above creates a completely new ofstream object from the one declared in the line in blue. The one in red only has scope within that single line statement. The line in red has the effect of opening and closing immediately. This ofstream object has nothing to do with the one declared in blue. Since the object in red only has scope in that one line where it is created, the line below where you attempt to write to the file is actually refering to the ofstream object in blue (the one you NEVER open). This is why nothing is ever written to the file.

This looks like it needs an array or two.
Something along these lines perhaps

Code:

#include <iostream>
#include <string>
#include <sstream>
#include <fstream>

using namespace std;

int main ( ) {
    char *filenames[] = {
        "january.all", "february.all",
    };
    ofstream files[12];
    ifstream source2;
    string s2Line;
    int g = 0;

    while ( getline(source2,s2Line) )
    {
        cout<<s2Line.substr(535,2)<<"  ";
        istringstream foo(s2Line.substr(535,2));
        int month;
        foo >> month;
        month--;    // convert from 1..12 to 0..11
        if ( !files[month] ) files[month].open(filenames[month]);
        files[month] << s2Line << endl;
    }
    return 0;
}