很久没有写c的程序了，拿个结构体来练练手 没想到编译虽然通过 但是执行报错：Segmentation fault

[view@localhost c]$cat s.c
#include<stdio.h>
typedef struct man{
        char *name;
        int age;
        char phone[12];
        }* pMAN;

int main(){
pMAN a;
strcpy(a->name,"hwt");
a->age=34;
strcpy(a->phone,"18677151934");
printf("a man named %s's age is %s,and phone is %s\n",a->name,a->age,a->phone);
exit(0);
}
[view@localhost c]$cc -o s s.c
[view@localhost c]$./s
Segmentation fault

新手

printf("a man named %s's age is %d,and phone is %s\n",a->name,a->age,a->phone);

这里改了，不过结果还是一样的报错。

#include<stdio.h>
#include <string.h>
#include <malloc.h>

typedef struct man{
        char *name;
        int age;
        char phone[12];
        }* pMAN;

int main(){
pMAN a = (pMAN) malloc(sizeof(struct man));
a->name = (char *) malloc(10);    // 你不给人家分配空间，人家往哪里 strcpy ？
strcpy(a->name,"hwt");
a->age=34;
strcpy(a->phone,"18677151934");
printf("a man named %s's age is %d,and phone is %s\n",a->name,a->age,a->phone);    // a->age 是 int, 用 %d
//exit(0);    // 这个不好，会让你看不到输出，除非你在退出前 fflush(stdout);
return 0;
}

[ 本帖最后由 voidx 于 2011-4-22 00:06 编辑 ]

自己改好了：
[view@localhost c]$cat s.c
#include<stdio.h>
typedef struct man{
        char name[10];
        int age;
        char phone[12];
        }* pMAN;

int main(){
pMAN a=(pMAN)malloc(sizeof(pMAN));
strcpy(a->name,"hwt");
a->age=34;
strcpy(a->phone,"18677151934");
printf("a man named %s's age is %d,and phone is %s\n",a->name,a->age,a->phone);
exit(0);
}
[view@localhost c]$cc -o s s.c
[view@localhost c]$./s
a man named hwt's age is 34,and phone is 18677151934

谢谢楼上的，那个char *name我改成name[10]才通过

pMAN a=(pMAN)malloc(sizeof(pMAN));    // 这个还是错的，而且要给 name 也分配空间，不然你定义个数组试试，肯定乱套

exit（0）没事的。我试过了。

这里声明已经改成name[10]了

你 printf("%d %d", sizeof(pMAN), sizeof(struct man)); 看一下就明白了，sizeof(struct man) 比 sizeof(pMAN) 大多了。
也就是说 pMAN a=(pMAN)malloc(sizeof(pMAN)); 分配的内存不够用。
之定义一个变量的时候没关系，但是如果你定义两个变量就不一样了。
你可以试一下下面的代码，跟你的代码完全一样，只是改成了两个变量

#include<stdio.h>
typedef struct man{
        char name[10];
        int age;
        char phone[12];
}* pMAN;

int main(){
    pMAN a=(pMAN)malloc(sizeof(pMAN)), b = (pMAN)malloc(sizeof(pMAN));
    strcpy(a->name,"hwt");
    a->age=34;
    strcpy(a->phone,"18677151934");strcpy(a->name,"hwt");
    strcpy(b->name,"hwt");
    b->age=34;
    strcpy(b->phone,"18677151934");
    printf("a man named %s's age is %d,and phone is %s\n",a->name,a->age,a->phone);
    printf("a man named %s's age is %d,and phone is %s\n",b->name,b->age,b->phone);
    exit(0);
}