C中十六进制字符串到字节数组

将十六进制字符串转换为字节数组的方法

c
#include 
#include 
#include 
// 将十六进制字符转换为对应的整数
int hexToInt(char hexChar) {
  if (hexChar >= '0' && hexChar <= '9') {
    return hexChar - '0';
  }
  else if (hexChar >= 'a' && hexChar <= 'f') {
    return hexChar - 'a' + 10;
  }
  else if (hexChar >= 'A' && hexChar <= 'F') {
    return hexChar - 'A' + 10;
  }
  else {
    return -1; // 非法字符
  }
}
// 将十六进制字符串转换为字节数组
void hexStringToByteArray(const char* hexString, unsigned char* byteArray, int byteArrayLength) {
  int hexStringLength = strlen(hexString);
  if (hexStringLength % 2 != 0 || hexStringLength / 2 > byteArrayLength) {
    return; // 非法输入
  }
  for (int i = 0; i < hexStringLength; i += 2) {
    int highNibble = hexToInt(hexString[i]);
    int lowNibble = hexToInt(hexString[i + 1]);
    if (highNibble == -1 || lowNibble == -1) {
      return; // 非法输入
    }
    byteArray[i / 2] = (highNibble << 4) | lowNibble;
  }
}
int main() {
  const char* hexString = "48656c6c6f20576f726c64";
  int byteArrayLength = strlen(hexString) / 2;
  unsigned char* byteArray = (unsigned char*)malloc(byteArrayLength * sizeof(unsigned char));
  hexStringToByteArray(hexString, byteArray, byteArrayLength);
  for (int i = 0; i < byteArrayLength; i++) {
    printf("%02x ", byteArray[i]);
  }
  printf("\n");
  free(byteArray);
  return 0;
}