匹配文件内容中的模式并计算出现次数

const COS = require('cos-nodejs-sdk-v5');
const fs = require('fs');
const readline = require('readline');

exports.main_handler = async (event, context, callback) => {
  // 从事件中获取上传的文件信息
  const { Bucket, Region, Key } = event.Records[0].cos;

  // 创建COS实例
  const cos = new COS({
    SecretId: 'your-secret-id',
    SecretKey: 'your-secret-key',
  });

  // 下载文件到本地临时目录
  const tempFilePath = '/tmp/tempfile.txt';
  await cos.getObject({
    Bucket,
    Region,
    Key,
    Output: fs.createWriteStream(tempFilePath),
  }).promise();

  // 逐行读取文件内容并匹配模式
  const rl = readline.createInterface({
    input: fs.createReadStream(tempFilePath),
    crlfDelay: Infinity,
  });

  const pattern = /your-pattern/g; // 替换为你的模式
  let count = 0;

  for await (const line of rl) {
    if (line.match(pattern)) {
      count++;
    }
  }

  // 输出结果
  console.log(`模式出现次数：${count}`);

  // 删除临时文件
  fs.unlinkSync(tempFilePath);

  // 返回结果
  callback(null, `模式出现次数：${count}`);
};