functions.js

document.querySelector("html").classList.add('js');

let fileInput  = document.querySelector( ".input-file" ),  
    button     = document.querySelector( ".input-file-trigger" ),
    the_return = document.querySelector(".file-return"),
    share_link = document.querySelector(".share-link"),
    note = document.querySelector("#note");
      
button.addEventListener( "keydown", function( event ) {  
    if ( event.keyCode == 13 || event.keyCode == 32 ) {  
        fileInput.focus();  
    }  
});
button.addEventListener( "click", function( event ) {
   fileInput.focus();
   return false;
});  
fileInput.addEventListener( "change", function( event ) {  
    // the_return.innerHTML = this.value;  
    let file_name = this.files[0].path.split('\\')[this.files[0].path.split('\\').length - 1];
    the_return.innerHTML = this.files[0].path;


    const crypto = require('crypto');
    let sha1 = crypto.createHash('sha1');
    sha1.update(file_name + new Date());
    let output = sha1.digest('hex').slice(0, 6);

    let ip = require('ip');
    ip_address = ip.address();


    let express = require('express');
    let app = express();
    app.get(`/${output}`, (req, res) => {
        let fs = require('fs');

        let stream = 
            fs.createReadStream(this.files[0].path.replace(/\\/g, '\\\\'), { bufferSize: 64 * 1024});  // 스트림 생성
        res.attachment(file_name);  // 파일 이름 지정
        stream.pipe(res);   // 스트림으로 응답
    });

    let port = 25548 + Math.floor(Math.random() * 300);

    app.listen(port).on('error', (err) => {alert(`PORT ${port} is already use.\nPlease Restart Application. :)`)});

    share_link.innerHTML = `Share link : http://${ip_address}:${port}/${output}`;
    note.innerHTML = `NOTE : If you are on NAT, <br>please <a target="_blank" href="https://en.wikipedia.org/wiki/Port_forwarding">'Port forwarding'</a> first.`;
});