* administriva -- Brandon out next week; no review section

* table driven programming overview
** goals -- what makes a good table driven design?
    1. simplify the code by shifting "logic" into a data structure
        very minimal to zero duplicated code
    2. makes modifications to support new settings trivial
        table update, no code update
** examples / ideas
*** showtty
    uses separate table for each flag type
    minimizes repeated code with the args to show_flagset
    adding an new setting for a supported flag -- just add a row to the table
    adding a new flag type
        add a table with settings
        add one call to show_flagset
    adding support to modify settings
        1. add a field to the table for the cli arg
        2. search the tables for a matching cli arg from argv
        3. use fl_value in the table to modify the flagset
*** could we just use a single table?
**** use function pointers to differentiate arg types
        void (*func)(type, type, type) <-- basically a standard function
                                           declaration but with (* ) around
                                           the name
        table.func(arg, arg, arg)
**** create and enum of constants for arg types and add a field
**** or maybe, just put a pointer to the flag value directly in the table

        declare the termios struct as a static global so you can reference
        the addresses in the table

        create the termios struct and table at function scope somewhere

**** offsetof(struct termios, c_lflag)
    

* review the termios struct
** mechanics
    each of the tcflag_t fields is a bit-array
    use bitwise operations to turn a setting on or off
       off: use the bitwise and operator with the bitwise complement
                ttyp->c_lflag &= ~table.fl_value
       on:  use the bitwise or operator
                ttyp->c_lflag |= table.fl_value
    c_cc -- just change the value in the array; the constant is an array index

** how changing settings works
    1. tcgetattr -- gets the current settings
    2. change everything the user asks for
    3. tcsetattr -- updates the settings to match the termios struct

* display of control chars
    read Bruce's write about control char display
    do some investigation into "<undef>"