C语言高级编程：字符串赋值的几种方式

1. 总结

1）下面两种方式的字符串赋值均正确

    char str1[] = "hello str1";

    char *str2  = "hello str2";

    char *str3;    str3  = "hello str3";

2）char str1[] = "hello str1";  是将字符串赋值给数组，字符串存在数组里（这里是栈），可以修改字符串内容，可读可写。

3） char *str2 = "hello str2";  是将字符串地址赋值给指针变量，字符串本身存在只读内存区，不可通过指针对其进行修改，只读不可写。

4）str3  = "hello str3";  同3）

2. 代码：

#include <stdio.h>
#include <stdlib.h>


void main(void)
{
    char str1[] = "hello str1";
    char *str2  = "hello str2";

    //str1[0] = 'a';
    //str2[0] = 'a';

    printf("str1: %s\n", str1);
    printf("str2: %s\n", str2);    
}

3. 结果：

baoli@ubuntu:~/c$ ./a.out

str1: hello str1

str2: hello str2

将上述代码两行注释去掉，编译，运行：

baoli@ubuntu:~/c$ ./a.out

Segmentation fault (core dumped)

4. gdb调试：gdb ./a.out

(gdb) run
Starting program: /home/baoli/c/a.out
warning: the debug information found in "/lib64/ld-2.19.so" does not match "/lib64/ld-linux-x86-64.so.2" (CRC mismatch).

Program received signal SIGSEGV, Segmentation fault.
0x00000000004005dc in main () at test.c:11
11        str2[0] = 'a';
(gdb)
(gdb) print str2
$1 = 0x4006b4 "hello str2"
(gdb) print str1
$2 = "aello str1"