memcpy函数实现(c语言)
second60 20180530
#include <stdio.h> #include <assert.h> void *memcpy_new(void *to, void *from, size_t size) { char *tempFrom = NULL; char *tempTo = NULL; assert( to && from ); /*先转型为字符指针,字符为一个字节*/ tempFrom = (char*)from; tempTo = (char*)to; while(size-- > 0) { *tempTo++ = *tempFrom++; } return to; }
int main() { char strSrc[] = "hello world"; char strDest[20]; memcpy_new(strDest, strSrc, 8); strDest[8] = '\0'; printf("str=%s\n",strDest); getchar(); return 0; }