memcpy一种实现方法

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 
 4 void* memncpy(void* dest, const void* src, int count){
 5     int i=0;
 6     //void *init_dest = dest;
 7     char* dest1 = (char*)dest;
 8     const char* src1 = (char*)src;
 9     for(;i<count;i++){
10         *dest1=*src1;
11         dest1++;
12         src1++;
13     }
14     return dest;
15 }
16 int main(void){
17     int num=3;
18     char str1[8] ="abcdefg";
19     char* str2 = (char*)malloc(8);
20      //str1= "abcdefg"; // error: incompatible types when assigning to type ‘char[8]’ from type ‘char *
21      str2= "hijklmn";
22     printf("1str1：%s \n",str1);
23     memncpy(str1,str2,num);
24     printf("2str1: %s \n",str1);
25     return 0;
26 }