每行打印一個結構體成員

例子

#include <stdio.h>
#include <pthread.h>

typedef struct
{
        int a;
        int b;
        int c;
        int d;
        pthread_mutex_t mutex;
}ex_st;

int main(void) {
        ex_st st = {1, 2, 3, 4, PTHREAD_MUTEX_INITIALIZER};
        printf("%d,%d,%d,%d\n", st.a, st.b, st.c, st.d);
        return 0;
}

技巧

默認情況下，gdb以一種“緊湊”的方式打印結構體。以上面代碼為例：

(gdb) n
15              printf("%d,%d,%d,%d\n", st.a, st.b, st.c, st.d);
(gdb) p st
$1 = {a = 1, b = 2, c = 3, d = 4, mutex = {__data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 0,
      __spins = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = '\000' <repeats 39 times>, __align = 0}}

可以看到結構體的顯示很混亂，尤其是結構體裡還嵌套著其它結構體時。

可以執行“set print pretty on”命令，這樣每行只會顯示結構體的一名成員，而且還會根據成員的定義層次進行縮進：

(gdb) set print pretty on
(gdb) p st
$2 = {
  a = 1,
  b = 2,
  c = 3,
  d = 4,
  mutex = {
    __data = {
      __lock = 0,
      __count = 0,
      __owner = 0,
      __nusers = 0,
      __kind = 0,
      __spins = 0,
      __list = {
        __prev = 0x0,
        __next = 0x0
      }
    },
    __size = '\000' <repeats 39 times>,
    __align = 0
  }
}

詳情參見gdb手冊

貢獻者

nanxiao