Outline for May 31, 2002

Handouts:The Dynamic Debbugger gdb

Reading: Johnsonbaugh and Kalin, pp.  679-702 (appendix of useful functions)

1.	Greetings and felicitations!

2.	Miscellaneous

a.	terminate program (exit); include <stdlib.h>

b.	sort array of data (qsort); include <stdlib.h>

c.	time of day (time, ctime); include <time.h>

d.	execute cvommand (system); include <stdlib.h>

3.	Debugging

a.	programs have bugs; find and fix them

b.	static debugging: insert debugging code into source, recompile and run

c.	dynamic debugging: look at the program as it runs, observing (and maybe changing) variables, etc.

4.	Static debugging 

a.	using printf to print variable values; mention %p (prints pointer value, usually as a hex integer)

b.	using printf to print where you are (ie, on function entry printf("in function\n");

c.	#ifdef DEBUG - #endif around the printfs so you can leave them in the source if you need them again

d.	assert(x) macro: assert(0 <= i && i <= n) causes program to exit with error message if (0 <= I && I <= n) is 
false; must include <assert.h>.  To delete, say #define NDEBUG and they will not be in the compiled code.

5.	Dynamic debugging

a.	debugging tool instruments executable program so it can be stopped, examined, altered, and continued inter-
actively

b.	go through the handout

c.	mention the "where" command which shows you the program stack