crypt_r() 例子？

Question

谁能给我一个关于如何使用函数 crypt_r() 的例子吗？

在手册页中，不清楚返回的 char * 字符串是指向函数本身内部(在堆中)分配的内存块，还是仍然指向静态内存，如 crypt()？

Answer 1

来自GNU手册:

The crypt_r function does the same thing as crypt, but takes an extraparameter which includes space for its result (among other things), soit can be reentrant. data->initialized must be cleared to zero beforethe first time crypt_r is called.

Kernel.org提供更多细节:

crypt_r() is a reentrant version of crypt(). The structure pointed toby data is used to store result data and bookkeeping information.Other than allocating it, the only thing that the caller should dowith this structure is to set data->initialized to zero before thefirst call to crypt_r().

crypt 和crypt_r 都返回指向加密密码的指针。当然，如果您使用 crypt_r，那么内存将位于您传递的 crypt_data 中。

根据要求编辑示例:

struct crypt_data data;
data.initialized = 0;

char *enc = crypt_r(key, salt, &data);
printf("EncryptedL %s\n", enc);