memmov实现

memcpy不支持重叠区域拷贝，但memmov支持。下面针对memmov，个人实现了一个简单的版本

<pre name="code" class="plain">#include <stdio.h>#include <string.h>void* m_memmov(void* dst, void* src, unsigned int cnt){char* s = (char*)src;char* d = (char*)dst;if(NULL == s || NULL == d || 0 == cnt)return dst;if(src >= dst || d >= s + cnt){while(cnt){*d++ = *s++;--cnt;}}else{d += (cnt - 1);s += (cnt - 1);while(cnt){*d-- = *s--;--cnt;}}return dst;}int main(){char p[100] = "123456789";m_memmov(p + 6, p, strlen(p));printf("data = %s\n", p + 6);return 0;}