source: CMT/v1r18p20041201/Visual/tcout.cxx @ 1

#include <stdio.h> 
#include <stdlib.h> 
#include <iostream> 
#include <fstream> 
 
using namespace std; 
 
char buf[256]; 
int index = 0; 
 
class mysb : public streambuf 
{ 
        int overflow (int c) 
        { 
                buf[index] = c; 
                buf[index + 1] = 0; 
                index++; 
                if ((index > 200) || (c == '\n')) 
                { 
                        printf ("> %s\n", buf); 
                        index = 0; 
                } 
                return (1); 
        } 
        int underflow () 
        { 
                return (EOF); 
        } 
}; 
 
int main () 
{ 
        mysb s; 
        streambuf* old; 
 
        ifstream f ("../mgr/requirements"); 
        if (f) 
        { 
                cout << "opened" << endl; 
                f.close (); 
        } 
 
        cout << "aaa" << endl; 
 
        old = cout.rdbuf (&s); 
        //cout = &s; 
 
        cout << "bbb" << endl; 
 
        old = cout.rdbuf (old); 
        //cout = old; 
 
        cout << "ccc" << endl; 
 
        return (0); 
}