The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference
by Nicolai M. Josuttis, Addison-Wesley, 1999
© Copyright Nicolai M. Josuttis 1999
#include <iostream>
#include <streambuf>
#include <cstdio>
// for write():
#ifdef _MSC_VER
# include <io.h>
#else
# include <unistd.h>
#endif
class fdoutbuf : public std::streambuf {
protected:
int fd; // file descriptor
public:
// constructor
fdoutbuf (int _fd) : fd(_fd) {
}
protected:
// write one character
virtual int_type overflow (int_type c) {
if (c != EOF) {
char z = c;
if (write (fd, &z, 1) != 1) {
return EOF;
}
}
return c;
}
// write multiple characters
virtual
std::streamsize xsputn (const char* s,
std::streamsize num) {
return write(fd,s,num);
}
};
class fdostream : public std::ostream {
protected:
fdoutbuf buf;
public:
fdostream (int fd) : std::ostream(0), buf(fd) {
rdbuf(&buf);
}
};