Problem : 
For years in Fortran95, I've been reading and writing files into various directories of my choice, thus keeping our data files in an orderly fashion. However, now I am shocked to find that you can't do anything like that in C++.

Please tell me if there is a way, and give me an example.

Environment : 
Intel C++ compiler for Linux*

Resolution : 

This is not a compiler issue. You need to have suitable access rights to the file. You can take help from system administrator to get suitable access rights for the file. I am providing a sample test case that I tried at my end in FC11 box. It works without issue.

// file_rw.cpp
//

#include <fstream>
#include <iostream>
using namespace std;

int main()
{
    char str[2000] ;
    fstream fs( "/testdir/prt1.txt", ios::in ) ;

    if(!fs) {
        cout << "Cannot open input file.n";
        return 1;
    }

    fstream ft( "/testdir/prt2.txt", ios::out | ios::in ) ;
    if(!ft) {
        cout << "Cannot open output file.n";
        return 1;
    }

    while ( !fs.eof() )
    {
        fs.getline(str, 2000 ) ;
        ft << str << endl;
    }
    fs.close () ;
    ft.close ();
    return 0;
}