c - 如何在 c 中将字符串转换为十六进制，反之亦然？

Question

如何在 c 中将字符串转换为十六进制，反之亦然。例如:像“thank you”这样的字符串到十六进制格式:7468616e6b20796f75 从十六进制 7468616e6b20796f75 到字符串:“thank you”。有什么方法可以做到这一点吗？

提前致谢

Answer 1

sprintf 和 sscanf 就足够了。

#include <stdio.h>
#include <string.h>

int main(void) {
  char text[] = "thank you";
  int len = strlen(text);

  char hex[100], string[50];

  // Convert text to hex.
  for (int i = 0, j = 0; i < len; ++i, j += 2)
    sprintf(hex + j, "%02x", text[i] & 0xff);

  printf("'%s' in hex is %s.\n", text, hex);

  // Convert the hex back to a string.
  len = strlen(hex);
  for (int i = 0, j = 0; j < len; ++i, j += 2) {
    int val[1];
    sscanf(hex + j, "%2x", val);
    string[i] = val[0];
    string[i + 1] = '\0';
  }

  printf("%s as a string is '%s'.\n", hex, string);

  return 0;
}

现在

$ ./a.out
'thank you' in hex is 7468616e6b20796f75.
7468616e6b20796f75 as a string is 'thank you'.