我怎么能知道哪里的内存段是全零 [英] How can I know where the segment of memory is all Zero

问题描述

我的意思是，我的malloc存储器段，也许1K也许20字节..
假设指针 PMEM
我怎么能知道内容 PMEM 所指向都是零或 \\ 0
。我知道 memcmp ，但第二个参数应该另一内存地​​址...
感谢名单

I mean, I malloc a segment of memory, maybe 1k maybe 20bytes.. assume the pointer is pMem How can I know the content pMem refered is all Zero or \0 . I know memcmp but the second parameter should another memory address... thanx

推荐答案

正如其他人已经建议你可能想的 memset的或释放calloc 。

As others have already suggested you probably want memset or calloc.

但如果你实际上要检查的内存区域都是零，你可以与自己进行比较，但移动一位。

But if you actually do want to check if a memory area is all zero, you can compare it with itself but shifted by one.

bool allZero = pMem[0] == '\0' && !memcmp(pMem, pMem + 1, length - 1);

，其中长度为你想成为零字节数。

where length is the number of bytes you want to be zero.

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