File associated with fstream object?

[Sanyi Benczik]

Is there a way to obtain the name of the file associated with a fstream
object?

For example if I have

using namespace std;
ofstream file("test.txt");

is there a function which evaluates to "test.txt"?

Thx,
Sanyi

 

[Jack Klein]

Is there a way to obtain the name of the file associated with a fstream
object?

For example if I have

using namespace std;
ofstream file("test.txt");

is there a function which evaluates to "test.txt"?

Thx,
Sanyi

There is no way to do this using standard C++. There might or might
not be a non-standard platform specific extension provided by your
compiler/OS combination. On some platforms, a single file may have
more than one name.

Of course you could always build an object that contained a
std::string with the name and a stream reference.

 

[Dietmar Kuehl]

On some platforms, a single file may have
more than one name.

.... or none at all:

std:fstream tmpfile("mytempfile");
std::remove("mytempfile");

This is fine eg. on POSIX platforms and, except for the use of the hardcoded
name, a pretty common technique to create temporary files which are to be
removed when the program dies for whatever reason.

Of course you could always build an object that contained a
std::string with the name and a stream reference.

.... or attach the name to your file object:

int const index = std::ios_base::xalloc();
std::string filename("file.name");
std:fstream file(filename.c_str());
file.pword(index) = const_cast<char*>(filename.c_str());
// ...
char const* name = static_cast<char*>(file.pword(index));