[转]常见C语言库函数源码（一）

memcpy和memmove功能基本上差不多，但是当源串和目标串有Overlap时，memmove可以正确处理，memcpy则不行。

void* memset(void* dest, int value, size_t num) {  assert(dest != NULL);  unsigned char* p_dest = (unsigned char*)dest;  while(num-- > 0)     *p_dest++ = (unsigned char)value;  return dest;}