Laboratory: Pointers to Functions

Summary:

Prerequisites: Sorting.

• Preparation
• Exercises
  • Exercise 1: Reverse Sorting
  • Exercise 2: Case-Insensitive Sorting
• For Those with Extra Time

Preparation

a. Log in to your MathLAN workstation. (Of course, you've probably already done that if you're reading this laboratory.)

b. Create a directory for this lab. I'd suggest Labs/FunctionPointers.

c. Make copies of these files. (Cross your fingers that I did not make a mistake in transcription.)

d. Pull out your K&R.

e. Figure out how to put everything into an executable.

f. Review the code in the various files.

Exercises

Exercise 1: Reverse Sorting

Do K&R 5.14 on p. 121. That problem reads

Modify the sort program to handle a -r flag, which indicates sorting in reverse (decreasing) order. Be sure that -r works with -n.

Exercise 2: Case-Insensitive Sorting

Do K&R 5.15 on p. 121. That problem reads

Add the option -f to fold upper and lower case together, so that case distinctions are not made during sorting; for example, a and A compare equal.

For Those with Extra Time

Do K&R 5.16 on p. 121. That problem reads

Add the -d (directory order) option, which makes comparisons only on letters, numbers, and blanks. Make sure that it works in conjunction with -f.