help.js

'use strict';

const pad = require('./util/pad');

const commands = [
  'alias [-p] [name=[value]]',
  'cat [-AbeEnstTv] [files ...]',
  'cd [dir]',
  'clear',
  'cp [-fnr] source ... dest',
  'echo [-eE] [arg ...]',
  'export [-p][id=[value]]',
  'false',
  'grep [-bHhinqsvw] [-m max] [--silent] [--include pattern] pattern [files ...]',
  'head [-nqv] <files ...>',
  'kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... or kill -l',
  'less [files ...]',
  'ls [-aAdFhilQrRStUwx1] [paths ...]',
  'mkdir [-pv] [directories ...]',
  'mv [-fnv] source ... dest',
  'pwd [files ...]',
  'rm [-frR] [files ...]',
  'sort [-chMnrR] [-o file] [files ...]',
  'source filename [arguments...]',
  'tail [options] <files ...>',
  'touch [-acm] [-d date] [-r ref] [--time word] file ...',
  'true',
  'unalias [-a] name [names ...]',
  'which [command]'
];

function chop(str, len) {
  let res = String(str).slice(0, len - 2);
  res = (res.length === len - 2) ? `${res}>` : res;
  return res;
}

module.exports = function () {
  const version = require('./../package.json').version;
  let result = '';

  result += `Cash, version ${version}\n`;
  result += `These shell commands are defined internally.  Type \`help\' to see this list.\n`;
  result += `Type \`help name\' to find out more about the function \`name\'.\n`;
  result += `Use \`info cash\' to find out more about the shell in general.\n`;
  result += `\n`;

  const half = Math.floor(commands.length / 2);
  const width = Math.floor((process.stdout.columns - 3) / 2);
  const lhalf = Math.ceil(commands.length / 2);
  const padding = ((commands.length % 2) === 1) ? 1 : 0;
  for (let i = 0; i < lhalf; ++i) {
    const colA = pad(chop(commands[i], width), width);
    const colB = pad(chop(commands[half + i + padding] || '', width), width);
    const line = (i === lhalf - 1) ? '' : '\n';
    result += ` ${colA} ${colB}${line}`;
  }

  return result;
};