cpp/io/c/ftell

Returns the current value of the file position indicator for the file stream.

If the stream is open in binary mode, the value obtained by this function is the number of bytes from the beginning of the file.

If the stream is open in text mode, the value returned by this function is unspecified and is only meaningful as the input to std.

Return value
File position indicator on success or if failure occurs. Also sets errno on failure.