地穴(): Pointer to integer without cast?

Question

啊!为什么编译器会提示？感谢您的帮助!

% gcc -o mine mine.c -lcrypt
mine.c: In function 'main':
mine.c:19:14: warning: assignment makes pointer from integer without a cast [enabled by default]
%

代码:

#define _X_OPEN_SOURCE
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

int main() {

    const char key[] = "hello world";
    const char salt[]="01";
    const int MAXIMUM_HASH_LENGTH = 2 + 11;
    int i=0;

    char *hash;

    long long hashes = 0L;

    while (1) {

        hash = crypt(key, salt); /* problem with this line... */
        if (hash[2] == '0') {
            int leading0s = 0;
            leading0s++;
            for (i=3; i < MAXIMUM_HASH_LENGTH; i++) {
                if (hash[i] != '0') break;

                leading0s++;
            }
            printf("Winner: %s has %d leading zeros.\n",
                    hash, leading0s);
            printf("\t--> Hash %lld.\n\n", hashes);
        }

        if (hashes != 0 && (hashes % 10000) == 0) {
            printf("Hash %d: %s\n", hashes, hash);
        }

        if (hashes== 1000000) break;
        hashes++;

    }

    return 1000;

}

Answer 1

尝试将“#define _X_OPEN_SOURCE”更改为“#define _XOPEN_SOURCE”。