逆向-还原代码之little-or-big (Interl 64)

// 源代码

#include <stdio.h>

/* * 2016/9/29 yu liang. */

int test_one(void) { int i=1; char *p=(char *)&i;

if(*p==1) printf("Little_endian "); // Little_endian else printf("Big_endian "); }

int checkCPU() { { union w { int a; char b; } c;

c.a = 1;

return(c.b ==1); // [little endian] } }

/* * 高字节存储在高地址是小端，高字节存储在低地址是大端 */ int test_two() { int *a = 1; // 内存表示为0x00000001.指向编号为 1 的地址

if ((char*)&a[3] == 1) // &a[3] = &a + 3 = &a + sizeof(int) * 3 = a + 12 ====> 1 + 12 = 0xD, 见 c/array/slipt.c 验证 printf("big "); else printf("small ");

printf("0x%x 0x%x 0x%x 0x%x 0x%x 0x%x ", &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]); // 0x1 0x5 0x9 0xd 0x11 0x15 } int test_thr() { union _test { int a; short b; }test;

test.a = 0x12345678;

if(test.b == 0x1234) printf("big ");

if(test.b == 0x5678) printf("small "); }

typedef unsigned char BYTE; int test_four() { unsigned int num,*p;

p = &num;

num = 0;

*(BYTE *)p = 0xff;

if(num == 0xff) { printf("The endian of cpu is little "); } else { // num == 0xff000000 printf("The endian of cpu is big "); } return 0; }

int main(void) { int ret = -1;

test_one();

ret = checkCPU(); if (ret == 1) printf("[little endian] "); // [little endian] else if (ret == 0) printf("[big endian] ");

test_two(); // small test_thr(); // small test_four(); // The endian of cpu is little

return 0; }