Sort Slippi Files by Matchup -- Windows EXE: https://drive.google.com/file/d/1odkwoMNoVpAYFyPRxh8bXQXPRH6-ima1/view?usp=sharing

sortSLPMU.js

const slp = require('slp-parser-js');
const SlippiGame = slp.default;
const path = require('path');
const fs = require('fs');
const _ = require('lodash');
const cliProgress = require("cli-progress");

const inputFolder = "./Slippi";
const outputFolder = "./sorted";

function generateVSFolderName(players) {
    const chars = players.map(p => slp.characters.getCharacterName(p.characterId));
    chars.sort();
    return chars.join(" vs. ");
}

function walk(dir) {
	let results = [];
	let list = fs.readdirSync(dir);
	_.each(list, (file) => {
	  file = path.join(dir, file);
	  let stat = fs.statSync(file);
	  if (stat && stat.isDirectory()) {
		// Recurse into a subdirectory
		results = results.concat(walk(file));
	  } else if (path.extname(file) === ".slp") {
		results.push(file);
	  }
	});
	return results;
}

function sortSLPMU() {
  const files = walk(inputFolder);
    const bar = new cliProgress.SingleBar({}, cliProgress.Presets.shades_classic);
    bar.start(files.length, 0);
    _.each(files, (file) => {
      try{
        const game = new SlippiGame(file);
        let settings = game.getSettings();
        const cpu = _.some(settings.players, (player) => player.type != 0);
        const notsingles = settings.players.length != 2;
        if (cpu || notsingles) { // only look for files against real players in a 1v1
          bar.setTotal(bar.getTotal() - 1);
          return;
        }
        const folderName = generateVSFolderName(settings.players);
        let outputDir = path.join(outputFolder, folderName);
        fs.mkdir(outputDir, { recursive: true }, (err) => {
            if (err) console.log(`mkdir ${err}`);
            fs.copyFile(file, path.join(outputDir, path.basename(file)), (err) => {if (err) console.log(`rename ${err}`);});
        });
        bar.increment();
      } catch (err) {
        console.log(err);
        fs.appendFileSync("./sort_log.txt", `${err.stack}\n\n`);
      }
    });
    bar.stop();
}

module.exports = sortSLPMU; // export for use in other scripts

if (require.main == module) sortSLPMU(); // if running from terminal call main

I use Node 10 (https://nodejs.org/dist/latest-v10.x/), haven't tried on Node 12

Windows EXE: https://drive.google.com/file/d/1odkwoMNoVpAYFyPRxh8bXQXPRH6-ima1/view?usp=sharing

Setup if not using exe

1. Download the file, put it in a folder, and navigate to that folder in CMD/terminal.
2. npm install slp-parser-js cli-progress
3. Put slippi files in a folder named Slippi next to the script.
4. node <script file name>.
5. hurray (maybe)

Need extra help? Come to the slippi discord (https://discord.gg/pPfEaW5) and ping Nikki in #support-and-bugs.