$ gdb main
......
(gdb) start
Breakpoint 1 at 0x80483b5: file main.c, line 5.
Starting program: /home/akaedu/main
main () at main.c:5
5 int sum = 0, i = 0;
(gdb) n
9 sum = 0;
(gdb) (直接回车)
10 scanf("%s", input);
(gdb) (直接回车)
12345
11 for (i = 0; input[i] != '\0'; i++)
(gdb) p input
$1 = "12345"
(gdb) l
6 char input[5];
7
8 while (1) {
9 sum = 0;
10 scanf("%s", input);
11 for (i = 0; input[i] != '\0'; i++)
12 sum = sum*10 + input[i] - '0';
13 printf("input=%d\n", sum);
14 }
15 return 0;
(gdb) b 12 if i == 4
Breakpoint 2 at 0x80483e6: file main.c, line 12.
(gdb) c
Continuing.
Breakpoint 2, main () at main.c:12
12 sum = sum*10 + input[i] - '0';
(gdb) p sum
$2 = 1234
(gdb) delete breakpoints
Delete all breakpoints? (y or n) y
(gdb) start
Breakpoint 1 at 0x80483b5: file main.c, line 5.
Starting program: /home/akaedu/main
main () at main.c:5
5 int sum = 0, i = 0;
(gdb) n
9 sum = 0;
(gdb) (直接回车)
10 scanf("%s", input);
(gdb) (直接回车)
12345
11 for (i = 0; input[i] != '\0'; i++)
(gdb) watch input[5]
Hardware watchpoint 2: input[5]
(gdb) i watchpoints
Num Type Disp Enb Address What
2 hw watchpoint keep y input[5]
(gdb) c
Continuing.
Hardware watchpoint 2: input[5]
Old value = 0 '\0'
New value = 1 '\001'
0x0804840c in main () at main.c:11
11 for (i = 0; input[i] != '\0'; i++)
(gdb) c
Continuing.
Hardware watchpoint 2: input[5]
Old value = 1 '\001'
New value = 2 '\002'
0x0804840c in main () at main.c:11
11 for (i = 0; input[i] != '\0'; i++)
(gdb) c
Continuing.
Hardware watchpoint 2: input[5]
Old value = 2 '\002'
New value = 3 '\003'
0x0804840c in main () at main.c:11
11 for (i = 0; input[i] != '\0'; i++)