Find N largest files in a directory (searches recursively)

scan-files.js

const fs = require('fs');
const path = require('path');


function scanDirectory(dirpath, allFiles) {
    // nodejs runs single threaded, so is thread-safe.
    // NO MUTEX. MISSION ACCOMPLISHED YAYY

    if (dirpath.fullpath !== undefined) {
        dirpath = dirpath.fullpath;
    }

    // had to use for...of because system calls caused exceptions as well
    // otherwise would have used map
    // for example, permission error for user
    // however this should be exempted for root, which is handled well here
    for (let eachPath of fs.readdirSync(dirpath)) {
        try {
            let fullpath = path.join(dirpath, eachPath);
            let statHere = fs.statSync(fullpath);
            let isFile = statHere.isFile() && !statHere.isSymbolicLink();
            let isDir = statHere.isDirectory() && !statHere.isSymbolicLink();

            if (isFile) {
                allFiles.push({
                    fullpath: fullpath,
                    filesize: statHere.size
                });
            } else if (isDir) {
                scanDirectory(fullpath, allFiles);
            }
        } catch (exc) {
            console.error('error while ls for', eachPath);
        }
    }

    // let everythingHere = fs.readdirSync(
    //     (dirpath.fullpath === undefined) ? dirpath : dirpath.fullpath
    // ).map(fs.statSync);
    // let filesHere = everythingHere.filter(each => each.isFile);
    // let dirsHere = everythingHere.filter(each => each.isDir);

    // console.log('files =', filesHere.length, '| dirs =', dirsHere.length);

    // filesHere.map(allFiles.push);
    // dirsHere.map(subdirpath => scanDirectory(subdirpath, allFiles));

}


async function main() {
    let rootPath = process.argv[2];
    let N = process.argv[3] === undefined ? 10 : process.argv[3];
    if (rootPath === undefined) {
        console.error('Please provide a root directory to scan for');
        process.exit(1);
    }

    var allFiles = [];
    await scanDirectory(rootPath, allFiles);
    console.log('total files', allFiles.length);

    // finding largest files
    let allFilesSorted = allFiles.sort((file1, file2) => file1.filesize < file2.filesize);
    console.log('top', N, 'largest files here');
    console.log(allFilesSorted.slice(0, N));
}

main();