代码如下 ，已注释出现问题地方，另外本人刚开始学，希望知道此种错误的调试方法。
注：在windows 平台和 Linux平台都调试过

void reverse_string(char *string)
{
    char *end=string;
    char *begin=string;
    char swap;

    if(string!=NULL&&*string!='\0') //字符指针不为空，且字符串不为空
    {   
     for(end=string;end!='\0';end++)
            ;
          end=end-1;                      //指针退回到‘/0’之前
   
        while(end>begin)
         {
        swap=*end;
        *end=*begin;            //交换前后值，问题处在这里
        *begin=swap;
        end--;
        begin++

         }
   
   
    }
}

入参是字符串指针 *string

int main (int argc,char * argv[])
{
    char *string="sdfasdfasdf";        

    reverse_string(string);

    printf("%s \n",string);

    return 1;
}

以上为主函数代码

不是这个问题，这两种方法定义是没有问题的。
crazyjudas@ubuntu:~$ make reverse_string
cc -Wall -g    reverse_string.c   -o reverse_string
reverse_string.c: In function ‘reverse_string’:
reverse_string.c:24:4: error: expected ‘;’ before ‘}’ token
make: *** [reverse_string] Error 1
crazyjudas@ubuntu:~$ make reverse_string
cc -Wall -g    reverse_string.c   -o reverse_string
crazyjudas@ubuntu:~$ ./reverse_string
Segmentation fault
crazyjudas@ubuntu:~$ make reverse_string
cc -Wall -g    reverse_string.c   -o reverse_string
crazyjudas@ubuntu:~$ ./reverse_string
Segmentation fault
crazyjudas@ubuntu:~$ valgrind ./reverse_string
==2367== Memcheck, a memory error detector
==2367== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==2367== Using Valgrind-3.6.1-Debian and LibVEX; rerun with -h for copyright info
==2367== Command: ./reverse_string
==2367==
==2367== Invalid read of size 1
==2367==    at 0x8048471: reverse_string (reverse_string.c:18)
==2367==    by 0x80484DC: main (reverse_string.c:35)
==2367==  Address 0xffffffff is not stack'd, malloc'd or (recently) free'd
==2367==
==2367==
==2367== Process terminating with default action of signal 11 (SIGSEGV)
==2367==  Access not within mapped region at address 0xFFFFFFFF
==2367==    at 0x8048471: reverse_string (reverse_string.c:18)
==2367==    by 0x80484DC: main (reverse_string.c:35)
==2367==  If you believe this happened as a result of a stack
==2367==  overflow in your program's main thread (unlikely but
==2367==  possible), you can try to increase the size of the
==2367==  main thread stack using the --main-stacksize= flag.
==2367==  The main thread stack size used in this run was 8388608.
==2367==
==2367== HEAP SUMMARY:
==2367==     in use at exit: 0 bytes in 0 blocks
==2367==   total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==2367==
==2367== All heap blocks were freed -- no leaks are possible
==2367==
==2367== For counts of detected and suppressed errors, rerun with: -v
==2367== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 11 from 6)

调试的结果是swap=*end; 出了问题 ， 不知道为什么会这样。
我按照你说的改了，还是这样。

恩那是第一次的 第二次没错误了 在第一次下面

crazyjudas@ubuntu:~$ make reverse_string
cc -Wall -g    reverse_string.c   -o reverse_string
reverse_string.c: In function ‘reverse_string’:
reverse_string.c:24:4: error: expected ‘;’ before ‘}’ token
make: *** [reverse_string] Error 1
crazyjudas@ubuntu:~$ make reverse_string
cc -Wall -g    reverse_string.c   -o reverse_string

恩 是的 在linux下成功了 成功了 怎么会犯这种错误 。
因为之前是在windows下编译的，我还加了这个*号，当时还是一直有问题，我等下再去看看原来的代码。 谢谢了