PAGETURNER

If they want to quit, do so

    <<<<<< REVIEW CLEANING SUBROUTINE >>>>>>

CLEAN

If they want to quit, do so

BOX

                         REVIEW                       

GO

   The C compiler invocation command line to define the constant 

   UNIX_ON, and to undefine the constant OTHERS_OFF would be:

            a   cc  ...  -UUNIX_ON  -DOTHERS_OFF

            b   cc  -UUNIX_ON  -UOTHERS_OFF  ...

            c   cc  -DUNIX_ON  ...  -UOTHERS_OFF  ...

 Select one: 

 That is correct!

 You've got it on the 2nd try.

 Good, you understand the concept!

 Sorry, try again.

 No, try one more time.

 Please review Topic 3:  Defining and Undefining Constants

FORGET2

   The correct choice is  c .  The position of the constant definition 

   within the command line is irrelevant.  In  a  and  b , the logic

   is wrong.  Recall that -D defines a constant and -U undefines it.

 Given the following compiler invocation line:

    cc  -DVAX=0  -DMC68000=16  update.c

 and the following code inside the function update.c:

              #ifdef  VAX

                  wordsize = 32;

              #else

                  wordsize = 16;

              #ifndef MC68000

                  clib = "/usr/lib/common";

              #else

                  clib = "/usr/lib/mc68";

              #endif

              #endif

   -------------------------------

 The values of wordsize and clib are:

   a  16 and "/usr/lib/common"   b  32 and "/usr/lib/mc68"

   c  32 and "/usr/lib/common"   d  16 and "/usr/lib/mc68"

 Select one: 

 That is correct!

 You've got it on the 2nd try.

 You've got it finally!

 Sorry, try again.

 No, try one more time.

 Please review Topic 5: Conditional Compilation Commands

FORGET3

   The correct choice is  b .  Since both constants VAX and mc68000 are

   defined, the ifdef evaluates to TRUE and ifndef evaluates to FALSE.