将数组的十六进制值转换为另一个数组的字符串值

Question

我正在尝试将一个数组的十六进制值转换为另一个数组的字符。这是唯一的方法，我能找到但不起作用。

感谢您的帮助!

char tmp[] = {0x81, 0x00, 0x00, 0x00, 0x12, 0x05};
char new[12];

for (int i = 0; i < 6; i++) {
    printf(" %x", tmp[i]);
    sprintf(new + i, "%x", tmp[i]);
}
for (int i = 0; i < 12; i++) {
        printf(" %c", new[i]);
}
printf("new: %s\n", new);

这是输出:

 81 0 0 0 12 5
 8 0 0 0 1 5
new: 800015

所以，它缺少一些字节......

Answer 1

可能

char tmp[] = {0x81, 0x00, 0x00, 0x00, 0x12, 0x05};
char new[6];

必须是

int tmp[] = {0x81, 0x00, 0x00, 0x00, 0x12, 0x05};
char new[6*2+1];

和

sprintf(tmp + i, "%x", tmp[i]);

必须是

sprintf(new + 2*i, "%02x", tmp[i]);

和

for (int i = 0; i < 6; i++) {
        printf(" %c", new[i]);
}

必须是

for (int i = 0; i < 6*2; i++) {
        printf(" %c", new[i]);
}

执行:

/tmp % ./a.out
 81 0 0 0 12 5 8 1 0 0 0 0 0 0 1 2 0 5new: 810000001205

在 valgrind 下:

/tmp % valgrind ./a.out
==15557== Memcheck, a memory error detector
==15557== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al.
==15557== Using Valgrind-3.8.1 and LibVEX; rerun with -h for copyright info
==15557== Command: ./a.out
==15557== 
 81 0 0 0 12 5 8 1 0 0 0 0 0 0 1 2 0 5new: 810000001205
==15557== 
==15557== HEAP SUMMARY:
==15557==     in use at exit: 0 bytes in 0 blocks
==15557==   total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==15557== 
==15557== All heap blocks were freed -- no leaks are possible
==15557== 
==15557== For counts of detected and suppressed errors, rerun with: -v
==15557== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 6 from 6)