fs

来源： https://stackoverflow.com/questions/63283396/using-fs-to-write-new-files-if-a-certain-url-is-found-and-remove-the-file-if-it

问题 Inside the .txt file there are 30.000 url to scrape, when I made the program I was testing it with 10 urls and everything was fine, as soon as I made the 30k url file .txt it crashes after few minutes, I think it starts to read the .txt file and then it crashes due memory issues, here is the console output and my code. What's the best way to handle such a file? FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory 1: 0x100ba0c4a node::Abort()

问题 I am looking at the docs for fs.watch https://nodejs.org/docs/latest/api/fs.html#fs_fs_watch_filename_options_listener How can I watch all files in the current directory, but ignore node_modules? 回答1: Doesn't look like it's possible. Just take a look at the path in the listener and do nothing if it starts with 'node_modules'. It can't be that much of a performance hit, unless you're constantly updating modules while node is running, which would be a little strange. 来源： https://stackoverflow

问题 I'm trying to download files to the filesystem in an electron app. My code, in the main thread, looks like this: const dir = `${__dirname}/media`; if (!fs.existsSync(dir)){ fs.mkdirSync(dir); } const file = fs.createWriteStream(`${dir}/${name}`); file.on("open", function() { const request = http.get(url, function(response) { response.pipe(file); response.on('end', function() { file.close(); ... }); }); request.on('error', function(err) { ... }); }); This works when running in development

问题 I am working with: MacOS Mojave Angular 8 node v12.12.0 npm v6.13.4 and trying to make Argon2 to work in my Angular 8 app. In order to use Argon2 it is required to install gcc and node-gyp globally. I did install them as indicated on the npm pages of Argon2. GCC v9 was installed. But, I had repeatedly problems executing: CXX=g++-9 npm install I kept getting errors about stdlib++ . I tried using Apple's CLang++ and got a successful build with: CXX=clang++ npm install I imported argon2 in my

问题 I want to copy image.png form /folder1 to /folder2 , how to do it? /folder1 image.png /folder2 Thanks! 回答1: Try something like this: var fs = require('fs'); var inStr = fs.createReadStream('/your/path/to/file'); var outStr = fs.createWriteStream('/your/path/to/destination'); inStr.pipe(outStr); Code is not tested, just written down from memory. 回答2: Or if you prefer callbacks: fs = require('fs') fs.readFile('folder1/image.png', function (err, data) { if (err) throw err; fs.writeFile('folder2

问题 I want to copy image.png form /folder1 to /folder2 , how to do it? /folder1 image.png /folder2 Thanks! 回答1: Try something like this: var fs = require('fs'); var inStr = fs.createReadStream('/your/path/to/file'); var outStr = fs.createWriteStream('/your/path/to/destination'); inStr.pipe(outStr); Code is not tested, just written down from memory. 回答2: Or if you prefer callbacks: fs = require('fs') fs.readFile('folder1/image.png', function (err, data) { if (err) throw err; fs.writeFile('folder2

问题 I am trying to simply replace a line in a text file using JavaScript. The idea is: var oldLine = 'This is the old line'; var newLine = 'This new line replaces the old line'; Now i want to specify a file, find the oldLine and replace it with the newLine and save it. Anyone who can help me here? 回答1: This should do it var fs = require('fs') fs.readFile(someFile, 'utf8', function (err,data) { var formatted = data.replace(/This is the old line/g, 'This new line replaces the old line'); fs

问题 I am trying to simply replace a line in a text file using JavaScript. The idea is: var oldLine = 'This is the old line'; var newLine = 'This new line replaces the old line'; Now i want to specify a file, find the oldLine and replace it with the newLine and save it. Anyone who can help me here? 回答1: This should do it var fs = require('fs') fs.readFile(someFile, 'utf8', function (err,data) { var formatted = data.replace(/This is the old line/g, 'This new line replaces the old line'); fs

问题 I am trying to simply replace a line in a text file using JavaScript. The idea is: var oldLine = 'This is the old line'; var newLine = 'This new line replaces the old line'; Now i want to specify a file, find the oldLine and replace it with the newLine and save it. Anyone who can help me here? 回答1: This should do it var fs = require('fs') fs.readFile(someFile, 'utf8', function (err,data) { var formatted = data.replace(/This is the old line/g, 'This new line replaces the old line'); fs