I suspect that by now compiled and run your code and found that you get a segmentation fault.
You are getting this because you create and open an ofstream
object within foo()
, which is then destroyed (and closed) at the end of foo
. When you attempt to write to the stream in main()
, you attempt to access a buffer which no longer exists.
One workaround to this is to make your filestr
object global. There are plenty of better ones!
Edit: Here is a better solution as suggested by @MSalters:
#include <iostream>
#include <fstream>
class scoped_cout_redirector
{
public:
scoped_cout_redirector(const std::string& filename)
:backup_(std::cout.rdbuf())
,filestr_(filename.c_str())
,sbuf_(filestr_.rdbuf())
{
std::cout.rdbuf(sbuf_);
}
~scoped_cout_redirector()
{
std::cout.rdbuf(backup_);
}
private:
scoped_cout_redirector();
scoped_cout_redirector(const scoped_cout_redirector& copy);
scoped_cout_redirector& operator =(const scoped_cout_redirector& assign);
std::streambuf* backup_;
std::ofstream filestr_;
std::streambuf* sbuf_;
};
int main()
{
{
scoped_cout_redirector file1("file1.txt");
std::cout << "This is written to the first file." << std::endl;
}
std::cout << "This is written to stdout." << std::endl;
{
scoped_cout_redirector file2("file2.txt");
std::cout << "This is written to the second file." << std::endl;
}
return 0;
}