Thread: seekg() Not Working

Hi,

For some reason, the following piece of code won't rewind the cursor position in the file stream:

Code:

// C++ Statements

std::ifstream FileStream;
FileStream.open("MyFile");

char c;

while(!FileStream.eof()) {
FileStream.get(c);
}

FileStream.seekg(0, std::ios::beg);

if(!FileStream.eof()) {
std::cout << "Not EOF" << std::endl;
}
else {
std::cout << "EOF" << std::endl;
}
// More C++ Statements

The output is "EOF," not "Not EOF."

But the following piece of code does rewind the stream:

Code:

// C++ Statements

std::ifstream FileStream;
FileStream.open("MyFile");

char c;

while(!FileStream.eof()) {
FileStream.get(c);
}

FileStream.close();
FileStream.open("MyFile");

if(!FileStream.eof()) {
std::cout << "Not EOF" << std::endl;
}
else {
std::cout << "EOF" << std::endl;
}
// More C++ Statements

In this case, the output is "Not EOF."

Can someone please tell me why the seekg() statement is not rewinding the stream position?

Thanks in advance for your help.

*****

I am using g++ in FC5.

Originally Posted by laserlight

Just curious, but did you actually try to read from the file in the first example? It is possible that a FileStream.clear() before the seekg would be sufficient for your code to work as expected.

I'm quite shure you are right.

Code:

while(!FileStream.eof()) {
     FileStream.get(c);
}

reads the file until eof. now the file is in error state ( eof ) and seekg is ignored.
clear() should help.
Kurt

FileStream.clear() worked like magiC++!

Thanks a lot, folks.