我需要将std :: cout的副本重定向到该文件.即我需要在控制台和文件中看到输出.如果我用这个：
// redirecting cout's output
#include <iostream>
#include <fstream>
using namespace std;
int main () {
streambuf *psbuf,*backup;
ofstream filestr;
filestr.open ("c:\\temp\\test.txt");
backup = cout.rdbuf(); // back up cout's streambuf
psbuf = filestr.rdbuf(); // get file's streambuf
cout.rdbuf(psbuf); // assign streambuf to cout
cout << "This is written to the file";
cout.rdbuf(backup); // restore cout's original streambuf
filestr.close();
return 0;
}
解决方法
您可以做的最简单的事情是创建一个输出流类来执行此操作：
#include <iostream>
#include <fstream>
class my_ostream
{
public:
my_ostream() : my_fstream("some_file.txt") {}; // check if opening file succeeded!!
// for regular output of variables and stuff
template<typename T> my_ostream& operator<<(const T& something)
{
std::cout << something;
my_fstream << something;
return *this;
}
// for manipulators like std::endl
typedef std::ostream& (*stream_function)(std::ostream&);
my_ostream& operator<<(stream_function func)
{
func(std::cout);
func(my_fstream);
return *this;
}
private:
std::ofstream my_fstream;
};
请参阅此代码的ideone链接：http://ideone.com/T5Cy1M我目前无法检查文件输出是否正确完成,尽管它不应该是一个问题.
