指针的realloc问题

[zkx2321]

一个char**变量，malloc了2个单位空间，并且存入了两个字符串；这时候realloc了1个空间。

问：
1、原两个空间的内容会不会被毁坏？
2、新分配的1个空间在+1方向，还是在-1方向？

[youyifang]

The realloc function changes the size of an allocated memory block.

The memblock argument points to the beginning of the memory block. If memblock is NULL, realloc behaves the same way as malloc and allocates a new block of size bytes.

If memblock is not NULL, it should be a pointer returned by a previous call to malloc, or realloc.

The size argument gives the new size of the block, in bytes. The contents of the block are unchanged up to the shorter of the new and old sizes, although the new block can be in a different location.

Because the new block can be in a new memory location, the pointer returned by realloc is not guaranteed to be the pointer passed through the memblock argument.

realloc calls malloc to use the C++ _set_new_mode function to set the new handler mode. The new handler mode indicates whether, on failure, malloc is to call the new handler routine as set by _set_new_handler.

By default, malloc does not call the new handler routine on failure to allocate memory. You can override this default behavior so that, when realloc fails to allocate memory, malloc calls the new handler routine in the same way that the new operator does when it fails for the same reason.

[yuhudie203]

realloc 再分配

1.不会破坏原来的内容
2.+1的方向

[MoXiaoRab]

[Quote=引用 2 楼 yuhudie203 的回复:]
realloc 再分配

1.不会破坏原来的内容
2.+1的方向
[/Quote]
补充下:连接在原来的空间的后面

[joneson118]

顶了！！！

[和黑1]

学习了！