everest% CC io7.C
everest% 


everest% a.out 
Enter a filename: foo
Could not open file: foo
everest% 


everest% a.out
Enter a filename: data1
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everest% 


everest% a.out
Enter a filename: io0.C
// File: io0.C
// 
// Demonstrating simple I/O in C++

#include <iostream.h>
#include <iomanip.h>    // for endl, setw(), etc

#define BUFLEN 8

typedef char buffer[BUFLEN] ;

main() {
   buffer buf1, buf2 ;

   cout << &buf1 << endl ;
   cout << &buf2 << endl ;

   cout << "Enter a filename: " ;
   cin >> buf2 ;
   cout << "You entered: " << buf2 << endl ;

   cout << "Enter another filename: " ;
   cin >> buf1 ;
   cout << "You entered: " << buf1 << endl ;

   cout << "First file name is: " << buf2 << endl ;
}
everest%