node.js修改文件数据流?

您还可以像这样使用 scramjet 来简化此操作:fs.createReadStream('input/file.txt') .pipe(new StringStream('utf-8')) .split('\n') // split every line .map(async (line) => await makeYourChangesTo(line)) // update the lines .join('\n') // join again .pipe(fs.createWriteStream('output/file.txt'))我想这比手动操作要容易.I need to copy one large data file to another destination with some modifications. fs.readFile and fs.writeFile are very slow. I need to read line by line, modify and write to new file. I found something like this:fs.stat(sourceFile, function(err, stat){ var filesize = stat.size; var readStream = fs.createReadStream(sourceFile); // HERE I want do some modifications with bytes readStream.pipe(fs.createWriteStream(destFile));})But how to make modifications ? I tried to get data with data eventreadStream.on('data', function(buffer){ var str = strToBytes(buffer); str.replace('hello', ''); // How to write ???});but don't understand how to write it to file: 解决方案 You should use transform stream and use pipes like this:fs.createReadStream('input/file.txt') .pipe(new YourTransformStream()) .pipe(fs.createWriteStream('output/file.txt'))Then it's just a matter of implementing the transform stream as in this docYou can also make this easier for you using scramjet like this:fs.createReadStream('input/file.txt') .pipe(new StringStream('utf-8')) .split('\n') // split every line .map(async (line) => await makeYourChangesTo(line)) // update the lines .join('\n') // join again .pipe(fs.createWriteStream('output/file.txt'))Which I suppose is easier than doing that manually. 这篇关于node.js修改文件数据流?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！