Private - Answer the offset from the start of the file corresponding to the beginning of the read buffer.
Answer the contents of the file between the two given positions
Return the next character in the file, or nil at eof
Store aCharacter on the file
Return the next character in the file, or nil at eof. Don’t advance the file pointer.
Answer the zero-based position from the start of the file
Set the file pointer to the zero-based position n
Return the current size of the file, in bytes
Truncate the file at the current position