strcpy deal with overlapping

最新推荐文章于 2021-07-16 19:08:08 发布

原创最新推荐文章于 2021-07-16 19:08:08 发布 · 622 阅读

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本文详细解析了memmove和strcpy函数的实现原理。通过具体的C语言代码示例，展示了如何进行内存移动及字符串复制，并解释了不同情况下memmove的工作方式。

char *strcpy(char *to, char *from)

{

memmove(to, from, 1+strlen(from));

return to;

}

void *

memmove (dest, source, length)
     char *dest;
     const char *source;
     unsigned length;
{
  char *d0 = dest;
  if (source < dest)
    /* Moving from low mem to hi mem; start at end.  */
    for (source += length, dest += length; length; --length)
      *--dest = *--source;
  else if (source != dest)
    {
      /* Moving from hi mem to low mem; start at beginning.  */
      for (; length; --length)
        *dest++ = *source++;
    }
  return (void *) d0;
}