为什么我的.exe文件执行后崩溃

Question

This is a program to store employee details and access them using pointer variables. The output is getting displayed but after printing the details the .exe file crashes.

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct Emp
{
    char name[30];
    int id;
    char gender[10],mobno[12];
};
int main()
{
   struct Emp *p;
   p=(struct Emp*)malloc(sizeof(struct Emp*));
   printf("\nEnter the employee name : ");
   scanf("%s",&p->name);
   printf("Enter the employee id : ");
   scanf("%d",&p->id);
   printf("Enter your gender : ");
   scanf("%s",&p->gender);
   printf("Enter employee number : ");
   scanf("%s",&p->mobno);

   printf("\nEmployee details:-\nEmployee id : %d\nEmployee name :: %s\nEmployee's Gender : %s\nEmployee's Mobile number : %s\n ",p->id,p->name,p->gender,p->mobno);
   free(p);
   return 0;
}

After displaying the output, the .exe file stops working. Could you help me?

Answer 1

1. You should malloc(sizeof(struct Emp)) , not sizeof(struct Emp*) . No asterisk, you're allocating space for a whole struct, not for a pointer to it.

2. You should scanf("%30s", p->name) . No & needed, p->name is already a pointer. Also, that 30 is very important , you have to limit the size of the scanned string to the available size, otherwise reading more than 30 characters would cause a buffer overflow (actually 29 if you count the \\0 added by %s ).

3. Same goes for both p->gender ( %10s , no & ) and p->mobno ( %12s , no & ).

Answer 2

malloc应该具有sizeof(struct Emp)而不是sizeof(struct Emp*)