Node file operation

Node Some file operation problems of

Common modules for reading files ：fs

Compress a file

It uses node-archiver

link ：https://github.com/archiverjs/node-archiver

/** *  Package the destination folder  * @param dirname  The directory where the package file or folder is located  * @param filename  Files to be packaged / Directory name , It's also packed zip name  */
 static async zip(dirname:string,filename:string){
    
      let archive = archiver('zip', {
    
          zlib: {
     level: 9 } //  Set compression level 
       });
       let output = fs.createWriteStream(dirname+`/${
      filename}.zip`);
       console.log("file is zipping!");
       archive.pipe(output);
       archive.directory(dirname+filename+"/",false);   
       await archive.finalize();

       console.log("Util.zip:"+fs.existsSync(dirname+`/${
      filename}.zip`));
}

File hash value

It uses node-crypto

/** *  Get file hash value  * @param path * @returns */
 function createFileHash256Sync(path:string):any {
    
    
    // Read a Buffer
    const buffer = fs.readFileSync(path);
    const fsHash = crypto.createHash('sha256');
 
    fsHash.update(buffer);
    const md5 = fsHash.digest('hex');
    return md5;
 }

Use Form-Data Send compressed file

Use node-FormData modular

Do remember import FormData = require(“form-data”); Otherwise, it comes with form-data Content only supports blob perhaps string

Pass on readStream

//  Fill in the file 
form.append("file",fs.createReadStream(zipPath),{
    
     contentType:"application/octet-stream"
 });


//  If you use form-data Pass on json object , To convert to string To pass 
//  Filling parameters 
form.append("parameters", JSON.stringify({
    
       "filehash":filehash,
       "boardType":config.boardType,
        "compileType":config.compileType
      }),{
    
         contentType:"application/json"
});

When sending after encapsulation node-fetch I won't support it form-data,request Supported by formData The format is very simple, and it is not encapsulated like the one we use from-data, So here we use other ways to send the request .

form-data Send a request

let form = new FormData();
form.append("file", fs.createReadStream(zipPath));
//  towards C Submit file data 
form.submit('http://10.33.200.1:8700/api/upload', function(err, res) {
    
      res.resume();
      return res.send({
    
      code:200,
      message:' success '
   })
});

got Send a request

Use got modular

link ：https://github.com/sindresorhus/got

npm install got

import {
    FormData} from "formdata-node"

// I assume Got >= 12.x is used for this example
import got from "got"

const form = new FormData()

form.set("greeting", "Hello, World!")

const data = await got.post("https://httpbin.org/post", {
    body: form}).json()

console.log(data.form.greeting) // => Hello, World!

Use after coding fetch

import {
    Readable} from "stream"

import {
    FormDataEncoder} from "form-data-encoder"
import {
    FormData} from "formdata-node"

// Note that `node-fetch` >= 3.x have builtin support for spec-compliant FormData, sou you'll only need the `form-data-encoder` if you use `node-fetch` <= 2.x.
import fetch from "node-fetch"

const form = new FormData()

form.set("field", "Some value")

const encoder = new FormDataEncoder(form)

const options = {
    
  method: "post",
  headers: encoder.headers,
  body: Readable.from(encoder)
}

await fetch("https://httpbin.org/post", options)

File Object to send fetch

import {
    FormData, File} from "formdata-node" // You can use `File` from fetch-blob >= 3.x

import fetch from "node-fetch"

const form = new FormData()
const file = new File(["My hovercraft is full of eels"], "file.txt")

form.set("file", file)

await fetch("https://httpbin.org/post", {
    method: "post", body: form})