File Explorer

1'use strict'2 3const fs = require('fs')4const { PassThrough, pipeline } = require('readable-stream')5const glob = require('glob')6 7const defaults = {8  ext: '.txt',9  help: 'help'10}11 12function isDirectory (path) {13  try {14    const stat = fs.lstatSync(path)15    return stat.isDirectory()16  } catch (err) {17    return false18  }19}20 21function helpMe (opts) {22  opts = Object.assign({}, defaults, opts)23 24  if (!opts.dir) {25    throw new Error('missing dir')26  }27 28  if (!isDirectory(opts.dir)) {29    throw new Error(`${opts.dir} is not a directory`)30  }31 32  return {33    createStream: createStream,34    toStdout: toStdout35  }36 37  function createStream (args) {38    if (typeof args === 'string') {39      args = args.split(' ')40    } else if (!args || args.length === 0) {41      args = [opts.help]42    }43 44    const out = new PassThrough()45    const re = new RegExp(args.map(function (arg) {46      return arg + '[a-zA-Z0-9]*'47    }).join('[ /]+'))48 49    glob(opts.dir + '/**/*' + opts.ext, function (err, files) {50      if (err) return out.emit('error', err)51 52      files = files.map(function (path) {53        const relative = path.replace(opts.dir, '').replace(/^\//, '')54        return { path, relative }55      }).filter(function (file) {56        return file.relative.match(re)57      })58 59      if (files.length === 0) {60        return out.emit('error', new Error('no such help file'))61      } else if (files.length > 1) {62        const exactMatch = files.find((file) => file.relative === `${args[0]}${opts.ext}`)63        if (!exactMatch) {64          out.write('There are ' + files.length + ' help pages ')65          out.write('that matches the given request, please disambiguate:\n')66          files.forEach(function (file) {67            out.write('  * ')68            out.write(file.relative.replace(opts.ext, ''))69            out.write('\n')70          })71          out.end()72          return73        }74        files = [exactMatch]75      }76 77      pipeline(fs.createReadStream(files[0].path), out, () => {})78    })79 80    return out81  }82 83  function toStdout (args) {84    createStream(args)85      .on('error', function () {86        console.log('no such help file\n')87        toStdout()88      })89      .pipe(process.stdout)90  }91}92 93module.exports = helpMe94