获取C中字符串常量的地址 [英] Get address of a string-constant in C

问题描述

我想获取C中字符串常量的地址。

  char * const MYCONST = StringString ; 
  

据我所知，const是保存在内存的文本/代码段中的。
当我尝试获取MYCONSt中第一个元素的地址时：

  printf（％p\n ，&（MYCONST））; 
  

结果我得到0x7fff15342e28，它在堆栈中，而不在Text / Code段中。
有人可以帮我获取C中字符串常量的地址吗？

// edit
我找不到正确的答案到目前为止：当我写

  char * const MYCONST1 = StringString; 
 printf（ MYCONST1的地址：％p\n，MYCONST1）; 
 
 char * const MYCONST2 = StringString; 
 printf（ MYCONST2的地址：％p\n，（void *）MYCONST2）; 
  

这是输出：

地址MYCONST1的地址：0x400b91

MYCONST2的地址：0x400b91

但是它们应该具有不同的地址，因为两者不同常数。
结果长度为7而不是像区域设置变量那样为0x7fffa5dd398c时，有人能解释我吗？

谢谢！

解决方案

Q： //编辑到目前为止，我找不到正确的答案：写时

  char * const MYCONST1 = StringString; 
 printf（ MYCONST1的地址：％p\n，MYCONST1）; 
 
 char * const MYCONST2 = StringString; 
 printf（ MYCONST2的地址：％p\n，（void *）MYCONST2）; 
  

这是输出：

  MYCONST1的地址：0x400b91 
 
 MYCONST2的地址：0x400b91 
  

但是它们应该有不同的地址，因为这些是不同的常量。

---

A：因为两个指针都指向相同的字符串文字。编译器进行优化，让它们共享相同的数据，从而共享相同的地址。尝试使用

  gcc program_name.c -O 
   
 
 
看看。您会看到不同的地址。
 
 
 
相对：两个指针的地址相同 
 
I would like to get the address of an string-constant in C. 
 char * const MYCONST = "StringString";
As far as I know consts are "saved" in the Text/Code Segment of the memory. 
When I try to get the address of the first element in MYCONSt:
 printf("%p\n",&(MYCONST));
As result I get  0x7fff15342e28, which is in the stack and not in the Text/Code segement. 
Can anybody please help me get the address of a string-constant in C?

//edit
I can't find the correct answer so far: When I write
  char * const MYCONST1 = "StringString";
  printf("Address of MYCONST1: %p\n",MYCONST1);

  char * const MYCONST2 = "StringString";
  printf("Address of MYCONST2: %p\n",(void*)MYCONST2);
this is the output:

Address of MYCONST1: 0x400b91

Address of MYCONST2: 0x400b91

But they should have different addresses, because the are different constants.
Can anybody explain me while the result has a length of seven and not 0x7fffa5dd398c like a locale variable.

Thanks!
解决方案
Q: //edit I can't find the correct answer so far: When I write
char * const MYCONST1 = "StringString";
printf("Address of MYCONST1: %p\n",MYCONST1);

char * const MYCONST2 = "StringString";
printf("Address of MYCONST2: %p\n",(void*)MYCONST2);
this is the output:
Address of MYCONST1: 0x400b91

Address of MYCONST2: 0x400b91
But they should have different addresses, because the are different constants. 



A:  Since both the pointers point to same string literal. Compiler optimizes and let them share the same data and hence same address. Try compiling your code with 
gcc program_name.c -O 
and see. You will see the addresses different.

Relative: Addresses of two pointers are same

                        
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