* general prep guidance for the exam
** start by completing the form:
   https://cscie28.dce.harvard.edu/~dce-lib215/final/
** review the sample finals
    - gives a sense of exam structure
** approach to study
*** review all of high-level notes from lecture
    - identify the system calls that were covered
    - identify important techniques for using the calls
    - useful to reread the chapter in the book about that lecture
*** enumerate all of the system calls
    - brief description of its purpose
    - brief description of usage
*** review the plans and code from all of the homework
*** review gradesheets ... if there's something that stands out from the
    grades as needing review
** in the exam, showing that you understand the broad strokes of usage
   is more important than all of the specific details of usage
    - comment the code with a terse explanation
    - remember to error check!

* using a console editor to write code for the exam
** this could be useful to get around the limitation of the web form
** also used for the oral exam
** if you're not familiar with vim or emacs (real coding editors), take
   a few minutes to learn nano

* hard links vs symlinks
** file system structures that represent this

    file: an inode in a filesystem that references where some data is stored
    hard link: name-to-inode mapping stored in a directory
               because an inode number is unique within a filesystem,
               the inode must be in the same filesystem as the hardlink
    directory: specific type of file that stores hard link information

    symlink: specific type of file that stores a name-to-path mapping
             a symlink has an object of its own in the filesystem
             the symlink file: has an inode number and a hard link in
             a directory to that inode

** good explanation of inode use for files here
   https://www.geeksforgeeks.org/file-systems-in-operating-system/

* turning on and off flags
** termios struct
** options for various system calls
* flags that can be set in termios

    raw mode: non-canonical -- char-by-char
    cooked mode: canonical -- line-by-line

    input modes: input control -- largely preprocessing chars from keyboard
    output modes: output control -- largely postprocessng chars to screen
    control modes: not used much today -- mostly related to modems and such
    local modes: changing basic device controls
                 echo chars as typed?
                 canonical vs non-canonical

    to set a mode flag (X is one of i o c l):
        c_Xflag |= MODE
    to get a mode flag
        (c_Xflag & MODE) == MODE
    to unset a mode flag
        c_Xflag &= ~MODE

    note that some modes have two bits, that's why get works as it does

* details of how itimer / struct tv works

    recommend reviewing alarmlib.c
    also, bounce_select.c example from concurrency