zhywpt-sp/utils/util/fileData.js

// import {
// 	TextEncoder,
// 	TextDecoder
// } from "text-decoding";


export function IntegerToHexString(num, nLen) {
	if (num == null) {
		let str = "";
		for (let i = 0; i < nLen; i++) {
			str += "0";
		}
		return str;
	}
	return HighAddZero(num.toString(16), nLen);
}
export function HighAddZero(str, nLen) {
	let length = str.length;
	let nAddLen = nLen - length;
	if (length > nLen) {
		str = str.substring(0, nLen);
	} else {
		for (let i = 0; i < nAddLen; i++) {
			str = "0" + str;
		}
	}
	return str;
}
export function AsciToHexString(strAsci, nLen) {
	let s = String(strAsci);
	let encoder = new TextEncoder("UTF-8");
	let bytes = encoder.encode(s);
	let strResult = HexToString(bytes);
	let strLen = strResult.length;
	if (strLen >= nLen) {
		strResult = strResult.substring(0, nLen);
	} else {
		let nAddLen = nLen - strLen;
		for (let i = 0; i < nAddLen; i++) {
			strResult += "0";
		}
	}
	return strResult;
}

const DIGITS_UPPER = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
            'E', 'F'
];
export function HexToString(inHex) {
	let i;
	let strResult = "";
	for (i = 0; i < inHex.length; i++) {
		strResult += DIGITS_UPPER[(0xF0 & inHex[i]) >>> 4];
		strResult += DIGITS_UPPER[inHex[i] & 0x0F];
	}
	return strResult;
}

/**
 * 十六进制转汉字
 *
 * @param {string} data
 * @returns {string}
 */
export function HexToStrig(data,charType=1) {
	
  let str = data.substring(data.length - 2);
  while (str === "00") {
    data = data.substring(0, data.length - 2);
    if (data.length === 0) {
      return "";
    }
    str = data.substring(data.length - 2);
  }
  const asd = hexStringToByteArray(data);
  try {
	  if(charType ==1){
		  str = new TextDecoder("GBK").decode(asd);
	  }else{
		  str = new TextDecoder("UTF-8").decode(asd);
	  }
    
  } catch (e) {
    console.error(e);
  }
  return str;
}

/**
 * 十六进制字符串转字节数组
 *
 * @param {string} str
 * @returns {Uint8Array}
 */
export function hexStringToByteArray(str) {
  if (!str) {
    return new Uint8Array();
  }
  const result = new Uint8Array(str.length / 2);
  for (let i = 0; i < str.length; i += 2) {
    result[i / 2] = parseInt(str.substr(i, 2), 16);
  }
  return result;
}

/**
 * 十六进制转十进制
 *
 * @param {string} data
 * @returns {string}
 */
export function HexToInt(data) {
  let num = -1;
  try {
    num = parseInt(data, 16);
  } catch (e) {
    console.error(e);
  }
  return num.toString();
}


function guessEncoding(bytes) {
  // 检查字节序列是否以 BOM（字节顺序标记）开头
  if (bytes[0] === 0xEF && bytes[1] === 0xBB && bytes[2] === 0xBF) {
    return 'UTF-8';
  } else if (bytes[0] === 0xFE && bytes[1] === 0xFF) {
    return 'UTF-16BE';
  } else if (bytes[0] === 0xFF && bytes[1] === 0xFE) {
    return 'UTF-16LE';
  } else {
    // 统计每个字节的频率
    let freq = {};
    for (let i = 0; i < bytes.length; i++) {
      let b = bytes[i];
      freq[b] = freq[b] ? freq[b] + 1 : 1;
    }

    // 检查是否存在 GBK 的特定字节序列
    if (freq[0x81] && freq[0x81] > 0 && freq[0x40] && freq[0x40] > 0) {
      return 'GBK';
    }

    // 如果没有特定的 GBK 字节序列，则假设为 UTF-8
    return 'UTF-8';
  }
}