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Check if a file is open
Returns true if the stream is currently associated with a file, and false otherwise.
To determine this, the function calls: rdbuf()->is_open()
The stream is associated with a file if either a previous call to member open succeeded or if the object was successfully constructed using the parameterized constructor, and close has not been called since.
Parameters
none
Return Value
true if a file is open, i.e. associated to this stream object.
false otherwise.
Example
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// ofstream::is_open
#include <iostream>
#include <fstream>
using namespace std;
int main () {
ofstream outfile;
outfile.open ("test.txt");
if (outfile.is_open())
{
outfile << "Output operation successfully performed\n";
outfile.close();
}
else
{
cout << "Error opening file";
}
return 0;
}
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This example uses is_open to check whether the file has successfully been opened; If so, it writes a sentence to the file, otherwise it prints out an error message.
Basic template member declaration
( basic_ofstream<charT,traits> )
See also
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