gdb 条件断点

01 #include
02
03 int main()
04 {
05     int cnt, len;
06     for (cnt = 0; cnt < 100000; cnt++)
07     {
08         printf("cnt = %d\n", cnt);
09         len = cnt + 10;
10     }
11 }


root@zengxiaolong:/tmp# gdb -q test
(gdb) l
1    #include
2   
3    int main()
4    {
5        int cnt, len;
6        for (cnt = 0; cnt < 100000; cnt++)
7        {
8            printf("cnt = %d\n", cnt);
9            len = cnt + 10;
10        }
(gdb) b test.c:8 if cnt == 5  // test.c的第8行，如果cnt等于5，将会设置断点
Breakpoint 1 at 0x804838e: file test.c, line 8.
(gdb) r
Starting program: /tmp/test
cnt = 0
cnt = 1
cnt = 2
cnt = 3
cnt = 4

Breakpoint 1, main () at test.c:8
8            printf("cnt = %d\n", cnt);
(gdb) watch len    // 此时监测len的变化
Hardware watchpoint 2: len
(gdb) c
Continuing.
cnt = 5
Hardware watchpoint 2: len

Old value = 14
New value = 15
main () at test.c:6
6        for (cnt = 0; cnt < 100000; cnt++)
(gdb)