#!/usr/bin/env node
console.log('hello world');

$ chmod 755 hello

$ ./hello
hello world

{
 "name": "hello",
 "bin": {
  "hello": "hello"
 }
}

$ npm link

$ hello
hello world

#!/usr/bin/env node
console.log('hello ', process.argv[2]);

$ ./hello tom
hello tom

#!/usr/bin/env node
var name = process.argv[2];
var exec = require('child_process').exec;

var child = exec('echo hello ' + name, function(err, stdout, stderr) {
 if (err) throw err;
 console.log(stdout);
});

$ ./hello tom
hello tom

npm install --save shelljs

#!/usr/bin/env node
var name = process.argv[2];
var shell = require("shelljs");

shell.exec("echo hello " + name);

require('shelljs/global');

if (!which('git')) {
 echo('Sorry, this script requires git');
 exit(1);
}

mkdir('-p', 'out/Release');
cp('-R', 'stuff/*', 'out/Release');

cd('lib');
ls('*.js').forEach(function(file) {
 sed('-i', 'BUILD_VERSION', 'v0.1.2', file);
 sed('-i', /.*REMOVE_THIS_LINE.*\n/, '', file);
 sed('-i', /.*REPLACE_LINE_WITH_MACRO.*\n/, cat('macro.js'), file);
});
cd('..');

if (exec('git commit -am "Auto-commit"').code !== 0) {
 echo('Error: Git commit failed');
 exit(1);
}

$ npm install --save yargs

#!/usr/bin/env node
var argv = require('yargs').argv;

console.log('hello ', argv.name);

$ hello --name=tom
hello tom

$ hello --name tom
hello tom

$ node hello --name=tom
[ 'node',
 '/path/to/myscript.js',
 '--name=tom' ]

var argv = require('yargs').argv;

// $ node hello --name=tom
// argv = {
//  name: tom
// };

$ hello -n tom
hello tom

#!/usr/bin/env node
var argv = require('yargs')
 .alias('n', 'name')
 .argv;

console.log('hello ', argv.n);

$ hello -n tom
hello tom
$ hello --name tom
hello tom

#!/usr/bin/env node
var argv = require('yargs').argv;

console.log('hello ', argv.n);
console.log(argv._);

$ hello A -n tom B C
hello tom
[ 'A', 'B', 'C' ]

#!/usr/bin/env node
var argv = require('yargs')
 .demand(['n'])
 .default({n: 'tom'})
 .describe({n: 'your name'})
 .argv;

console.log('hello ', argv.n);

#!/usr/bin/env node
var argv = require('yargs')
 .option('n', {
  alias : 'name',
  demand: true,
  default: 'tom',
  describe: 'your name',
  type: 'string'
 })
 .argv;

console.log('hello ', argv.n);

#!/usr/bin/env node
var argv = require('yargs')
 .boolean(['n'])
 .argv;

console.log('hello ', argv.n);

$ hello
hello false
$ hello -n
hello true
$ hello -n tom
hello true

#!/usr/bin/env node
var argv = require('yargs')
 .option('n', {
  boolean: true
 })
 .argv;

console.log('hello ', argv.n);

#!/usr/bin/env node
var argv = require('yargs')
 .option('f', {
  alias : 'name',
  demand: true,
  default: 'tom',
  describe: 'your name',
  type: 'string'
 })
 .usage('Usage: hello [options]')
 .example('hello -n tom', 'say hello to Tom')
 .help('h')
 .alias('h', 'help')
 .epilog('copyright 2015')
 .argv;

console.log('hello ', argv.n);

$ hello -h

Usage: hello [options]

Options:
 -f, --name your name [string] [required] [default: "tom"]
 -h, --help Show help [boolean]

Examples:
 hello -n tom say hello to Tom

copyright 2015

#!/usr/bin/env node
var argv = require('yargs')
 .command("morning", "good morning", function (yargs) {
  console.log("Good Morning");
 })
 .command("evening", "good evening", function (yargs) {
  console.log("Good Evening");
 })
 .argv;

console.log('hello ', argv.n);

$ hello morning -n tom
Good Morning
hello tom

#!/usr/bin/env node
require('shelljs/global');
var argv = require('yargs')
 .command("morning", "good morning", function (yargs) {
  echo("Good Morning");
 })
 .command("evening", "good evening", function (yargs) {
  echo("Good Evening");
 })
 .argv;

console.log('hello ', argv.n);

#!/usr/bin/env node
require('shelljs/global');
var argv = require('yargs')
 .command("morning", "good morning", function (yargs) { 
  echo("Good Morning");
  var argv = yargs.reset()
   .option("m", {
    alias: "message",
    description: "provide any sentence"
   })
   .help("h")
   .alias("h", "help")
   .argv;

  echo(argv.m);
 })
 .argv;

$ hello morning -m "Are you hungry?"
Good Morning
Are you hungry?

if (err) {
 process.exit(1);
} else {
 process.exit(0);
}

$ ps aux | grep 'node'

process.stdin.resume();
process.stdin.setEncoding('utf8');
process.stdin.on('data', function(data) {
 process.stdout.write(data);
});

$ echo 'foo' | ./hello
hello foo

process.on('SIGINT', function () {
 console.log('Got a SIGINT');
 process.exit(0);
});

$ kill -s SIGINT [process_id]