ubuntuvm@ubuntuvm-VirtualBox:~/stack_overflow$ gdb so_ans -q
Reading symbols from so_ans...done.
(gdb) list 1
1	#include <stdio.h>
2	#include <stdlib.h>
3	#include <string.h>
4
5	int check_answer(char *ans) {
6
7	  int ans_flag = 0;
8	  char ans_buf[16];
9
10	  strcpy(ans_buf, ans);
(gdb) list
11
12	  if (strcmp(ans_buf, "forty-two") == 0)
13	    ans_flag = 1;
14
15	  return ans_flag;
16
17	}
18
19	int main(int argc, char *argv[]) {
20
(gdb) list
21	  if (argc < 2) {
22	    printf("Usage: %s <answer>\n", argv[0]);
23	    exit(0);
24	  }
25	  if (check_answer(argv[1])) {
26	    printf("Right answer!\n");
27	  } else {
28	    printf("Wrong answer!\n");
29	  }
30
(gdb) break 10
Breakpoint 1 at 0x400660: file ans_check.c, line 10.
(gdb) break 15
Breakpoint 2 at 0x40068f: file ans_check.c, line 15.
(gdb) run 11111111111111111111111111111
Starting program: /home/ubuntuvm/stack_overflow/so_ans 11111111111111111111111111111

Breakpoint 1, check_answer (ans=0x7fffffffe367 '1' <repeats 29 times>)
    at ans_check.c:10
10	  strcpy(ans_buf, ans);
(gdb)
(gdb) x/s ans_buf
0x7fffffffdec0:	"\001"
(gdb) x/xw &ans_flag
0x7fffffffdedc:	0x00000000
(gdb) c
Continuing.

Breakpoint 2, check_answer (ans=0x7fffffffe367 '1' <repeats 29 times>)
    at ans_check.c:15
15	  return ans_flag;
(gdb) c
Continuing.
Right answer!
[Inferior 1 (process 2766) exited with code 016]
(gdb) x/s ans_buf
No symbol "ans_buf" in current context.
(gdb) exit
Undefined command: "exit".  Try "help".
(gdb) quit
ubuntuvm@ubuntuvm-VirtualBox:~/stack_overflow$ clear

ubuntuvm@ubuntuvm-VirtualBox:~/stack_overflow$ gdb so_ans -q
Reading symbols from so_ans...done.
(gdb) list 1
1	#include <stdio.h>
2	#include <stdlib.h>
3	#include <string.h>
4
5	int check_answer(char *ans) {
6
7	  int ans_flag = 0;
8	  char ans_buf[16];
9
10	  strcpy(ans_buf, ans);
(gdb) list
11
12	  if (strcmp(ans_buf, "forty-two") == 0)
13	    ans_flag = 1;
14
15	  return ans_flag;
16
17	}
18
19	int main(int argc, char *argv[]) {
20
(gdb) list
21	  if (argc < 2) {
22	    printf("Usage: %s <answer>\n", argv[0]);
23	    exit(0);
24	  }
25	  if (check_answer(argv[1])) {
26	    printf("Right answer!\n");
27	  } else {
28	    printf("Wrong answer!\n");
29	  }
30
(gdb) break 10
Breakpoint 1 at 0x400660: file ans_check.c, line 10.
(gdb) break 15
Breakpoint 2 at 0x40068f: file ans_check.c, line 15.
(gdb) run 11111111111111111111111111111
Starting program: /home/ubuntuvm/stack_overflow/so_ans 11111111111111111111111111111

Breakpoint 1, check_answer (ans=0x7fffffffe367 '1' <repeats 29 times>)
    at ans_check.c:10
10	  strcpy(ans_buf, ans);
(gdb) x/s ans_buf
0x7fffffffdec0:	"\001"
(gdb) x/xw &ans_flag
0x7fffffffdedc:	0x00000000
(gdb) c
Continuing.

Breakpoint 2, check_answer (ans=0x7fffffffe367 '1' <repeats 29 times>)
    at ans_check.c:15
15	  return ans_flag;
(gdb) x/s ans_buf
0x7fffffffdec0:	'1' <repeats 29 times>
(gdb) x/xw &ans_flag
0x7fffffffdedc:	0x00000031
(gdb)