rewind Rewind the position of a file pointer intrewind intfp Sets the file position indicator for fp to the beginning of the file stream. If an error occurs, returns 0, otherwise it returns 1. The file pointer must be valid, and must point to a file successfully opened by fopen. If you have opened the file in append ("a") mode, any data you write to the file will always be appended, regardless of the file position. See also fseek and ftell.