brock@burningtown:~/csci235/labs/clab_make$ gdb blastoff 
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Reading symbols from blastoff...done.
(gdb) list
1	#include <stdio.h>
2	#include <stdlib.h>
3	
4	#include "countDown.h"
5	
6	int main (int argc, char *argv[]) {
7	  int n ;
8	  puts("Mission control: Initialize countdown sequence!") ;
9	  int numRead = scanf("%d", &n) ;
10	  if (numRead < 1) {
(gdb) break 9
Breakpoint 1 at 0x400606: file blastoff.c, line 9.
(gdb) run
Starting program: /home/brock/public_html/classes/Fall2017/csci235/labs/clab_make/blastoff 
Mission control: Initialize countdown sequence!

Breakpoint 1, main (argc=1, argv=0x7fffffffea58) at blastoff.c:9
9	  int numRead = scanf("%d", &n) ;
(gdb) step
__isoc99_scanf (format=0x400748 "%d") at isoc99_scanf.c:27
27	isoc99_scanf.c: No such file or directory.
(gdb) fin
Run till exit from #0  __isoc99_scanf (format=0x400748 "%d")
    at isoc99_scanf.c:27
12
0x000000000040061c in main (argc=1, argv=0x7fffffffea58) at blastoff.c:9
9	  int numRead = scanf("%d", &n) ;
Value returned is $1 = 1
(gdb) step
10	  if (numRead < 1) {
(gdb) step
14	  countDown(n) ;
(gdb) step
countDown (start=12) at countDown.c:4
4	  for (int i=start; i>0; --i) {
(gdb) step
5	    printf("%2d\n", i) ;
(gdb) step
__printf (format=0x40075e "%2d\n") at printf.c:28
28	printf.c: No such file or directory.
(gdb) fin
Run till exit from #0  __printf (format=0x40075e "%2d\n") at printf.c:28
12
countDown (start=12) at countDown.c:4
4	  for (int i=start; i>0; --i) {
Value returned is $2 = 3
(gdb) step
5	    printf("%2d\n", i) ;
(gdb) next
11
4	  for (int i=start; i>0; --i) {
(gdb) n
5	    printf("%2d\n", i) ;
(gdb) n
10
4	  for (int i=start; i>0; --i) {
(gdb) n
5	    printf("%2d\n", i) ;
(gdb) n
 9
4	  for (int i=start; i>0; --i) {
(gdb) n
5	    printf("%2d\n", i) ;
(gdb) n
 8
4	  for (int i=start; i>0; --i) {
(gdb) n
5	    printf("%2d\n", i) ;
(gdb) print i
$3 = 7
(gdb) fin
Run till exit from #0  countDown (start=12) at countDown.c:5
 7
 6
 5
 4
 3
 2
 1
blastoff!
main (argc=1, argv=0x7fffffffea58) at blastoff.c:15
15	  return 0 ;
(gdb)