Setting a file stream to std[in/out/err]?

[masood.iqbal]

In the stdio library, supported by C, we can set a file pointer to
stdin or stdout ot stderr (e.g. FILE* fp = stdin. Can we do
something similar with ifstream and ofstream in C++? i.e. can we set
the ifstream to stdin and the ofstream to stdout or stderr? If the
answer is yes, please provide a code snippet.

Thanks,
Masood

 

[Ondra Holub]

In the stdio library, supported by C, we can set a file pointer to
stdin or stdout ot stderr (e.g. FILE* fp = stdin. Can we do
something similar with ifstream and ofstream in C++? i.e. can we set
the ifstream to stdin and the ofstream to stdout or stderr? If the
answer is yes, please provide a code snippet.

Thanks,
Masood

Do all your stuff in some function or method:

#include <iostream>
#include <fstream>

void DoSomethingWithStream(std:stream& os)
{
os << "Do something here\n";
}

int main()
{
// You can call DoSomethingWithStream with ostream as well as with
ofstream
std:fstream ifs("filename", std::ios::in);
DoSomethingWithStream(ifs);
ifs.close();

DoSomethingWithStream(std::cout);
}

 

[hurcan solter]

In the stdio library, supported by C, we can set a file pointer to
stdin or stdout ot stderr (e.g. FILE* fp = stdin. Can we do
something similar with ifstream and ofstream in C++? i.e. can we set
the ifstream to stdin and the ofstream to stdout or stderr? If the
answer is yes, please provide a code snippet.

Thanks,
Masood

std:fstream file("sil.txt",ios:ut);

std::cout.rdbuf(file.rdbuf());

std::cout<<"this goes to the file"<<std::endl;