使用'sprintf'将十六进制转换为字符串

Question

我正在尝试将数组转换为十六进制，然后将其放入一个字符串变量中。在以下循环中printf工作正常，但我不能正确使用sprintf。如何将十六进制值作为ASCII填充到数组中？

static unsigned char  digest[16];
static unsigned char hex_tmp[16];

for (i = 0; i < 16; i++) {
  printf("%02x",digest[i]);  <--- WORKS
  sprintf(&hex_tmp[i], "%02x", digest[i]);  <--- DOES NOT WORK!
}

Answer 1

static unsigned char  digest[16];
static char hex_tmp[33];

for (i = 0; i < 16; i++)  {
  printf("%02x",digest[i]);  <--- WORKS
  sprintf(&hex_tmp[i*2],"%02x", digest[i]);  <--- WORKS NOW
}

Answer 2

也许你需要：

&hex_tmp[i * 2]

还有一个更大的阵列。

Answer 3

存储为数字的字符与字符串不同：

unsigned char i = 255;
unsigned char* str = "FF";
unsigned char arr1[] = { 'F', 'F', '\0' };
unsigned char arr2[] = { 70, 70, 0 };