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c++ifstreamseekg

Maintaining a valid position using seekg in ifstreams

I am trying to make my file parsing more robust. Using an ifstream, how can I ensure seekg keeps me in a valid position within the file?

This does not work:

while(m_File.good() && m_File.peek() != EOF)
{ ...a seekg operation moves file position past end of file... }

I assume the current iterator has been pushed way past the end iterator, so the peek() is never true.

Solution

  • No, there is no way of doing this, short of finding the offset of the end of file and making sure you don't seek beyond it, which causes undefined behaviour - you can of course increase the size of the file by writing.