public member function

std::filebuf::is_open

<fstream>
bool is_open ( );
Check if a file is open
The function returns true if a previous call to open succeeded and there have been no calls to the member close since, meaning that the filebuf object is currently associated with a file.

Parameters

none

Return Value

true if a file is open, i.e. associated to this stream buffer object.
false otherwise.

Example

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// is_open () example
#include <iostream>
#include <fstream>
using namespace std;

int main () {

  ifstream is;
  filebuf * fb;

  fb = is.rdbuf();
  fb->open ("test.txt",ios::in);

  if ( fb->is_open() )
    cout << "file is open.\n";
  else
    cout << "file is not open.\n";

  fb->close();

  return 0;
}


Basic template member declaration

( basic_filebuf<charT,traits> )
 
 
bool is_open ( );


See also

filebuf::open
Open file (public member function)
filebuf::close
Close file (public member function)