我会使用双工流代替。就像这里记录的nodejs doc双工流

Transform流是计算输出的双工流 离输入有一段距离。

也许“replace”模块(www.npmjs.org/package/replace)也适合您。它不需要您读取然后写入文件。

改编自文档:

// install:

npm install replace 

// require:

var replace = require("replace");

// use:

replace({
    regex: "string to be replaced",
    replacement: "replacement string",
    paths: ['path/to/your/file'],
    recursive: true,
    silent: true,
});

你也可以使用'sed'函数，它是ShellJS的一部分…

 $ npm install [-g] shelljs


 require('shelljs/global');
 sed('-i', 'search_pattern', 'replace_pattern', file);

完整的文档…

ShellJS - sed（） ShellJS

您可以使用流在读取文件时处理该文件。这就像使用缓冲区，但使用了更方便的API。

var fs = require('fs');
function searchReplaceFile(regexpFind, replace, cssFileName) {
    var file = fs.createReadStream(cssFileName, 'utf8');
    var newCss = '';

    file.on('data', function (chunk) {
        newCss += chunk.toString().replace(regexpFind, replace);
    });

    file.on('end', function () {
        fs.writeFile(cssFileName, newCss, function(err) {
            if (err) {
                return console.log(err);
            } else {
                console.log('Updated!');
            }
    });
});

searchReplaceFile(/foo/g, 'bar', 'file.txt');

你可以使用简单的正则表达式:

var result = fileAsString.replace(/string to be replaced/g, 'replacement');

所以…

var fs = require('fs')
fs.readFile(someFile, 'utf8', function (err,data) {
  if (err) {
    return console.log(err);
  }
  var result = data.replace(/string to be replaced/g, 'replacement');

  fs.writeFile(someFile, result, 'utf8', function (err) {
     if (err) return console.log(err);
  });
});

扩展@Sanbor的回答，最有效的方法是将原始文件作为流读取，然后也将每个块流到一个新文件中，然后最后用新文件替换原始文件。

async function findAndReplaceFile(regexFindPattern, replaceValue, originalFile) {
  const updatedFile = `${originalFile}.updated`;

  return new Promise((resolve, reject) => {
    const readStream = fs.createReadStream(originalFile, { encoding: 'utf8', autoClose: true });
    const writeStream = fs.createWriteStream(updatedFile, { encoding: 'utf8', autoClose: true });

    // For each chunk, do the find & replace, and write it to the new file stream
    readStream.on('data', (chunk) => {
      chunk = chunk.toString().replace(regexFindPattern, replaceValue);
      writeStream.write(chunk);
    });

    // Once we've finished reading the original file...
    readStream.on('end', () => {
      writeStream.end(); // emits 'finish' event, executes below statement
    });

    // Replace the original file with the updated file
    writeStream.on('finish', async () => {
      try {
        await _renameFile(originalFile, updatedFile);
        resolve();
      } catch (error) {
        reject(`Error: Error renaming ${originalFile} to ${updatedFile} => ${error.message}`);
      }
    });

    readStream.on('error', (error) => reject(`Error: Error reading ${originalFile} => ${error.message}`));
    writeStream.on('error', (error) => reject(`Error: Error writing to ${updatedFile} => ${error.message}`));
  });
}

async function _renameFile(oldPath, newPath) {
  return new Promise((resolve, reject) => {
    fs.rename(oldPath, newPath, (error) => {
      if (error) {
        reject(error);
      } else {
        resolve();
      }
    });
  });
}

// Testing it...
(async () => {
  try {
    await findAndReplaceFile(/"some regex"/g, "someReplaceValue", "someFilePath");
  } catch(error) {
    console.log(error);
  }
})()