search installed application

Red Hat/Fedora Core/CentOS Linux

Type the following command to get list of all installed software
# rpm -qa | less

Debian Linux

Type the following command to get list of all installed software:
# dpkg --get-selections

Ubuntu Linux

Type the following command to get list of all installed software:
# sudo dpkg --get-selections

FreeBSD

Type the following command to get list of all installed software:
# pkg_info | less
# pkg_info apache

Use pkg_version command to summarizes the versions of all installed packages:
# pkg_version | less
# pkg_version | grep 'lsof'

OpenBSD

OpenBSD also use pkg_info command to display list of all installed packages or software:
# pkg_info | less
# pkg_info apache

express_example_setup_locally

$ mkdir myapp
$ cd myapp

$ npm init

$ npm install express --save

$ npm install express

export NODE_PATH=/usr/local/lib/node_modules

=======================

=======================

helloworld.js

var express = require('express');

var app = express();



app.get('/', function(req, res){

  res.send('Hello World');

});



app.listen(80);

mount ubuntu ，共用資料夾，share folder

mount -t vboxsf folderInMac folderInUbuntu

express node.js problem ubuntu

express expressproject
cd expressproject
npm install

install dependencies:
 $ cd mytestapp && npm install

run the app:
 $ DEBUG=my-application ./bin/www

npm cheat sheet

Listing globally installed NPM packages and version

npm list -g --depth=0

network monitor linux, command lsof

http://www.tecmint.com/10-lsof-command-examples-in-linux/

1. List all Open Files with lsof Command

2. List User Specific Opened Files

3. Find Processes running on Specific Port

4. List Only IPv4 & IPv6 Open Files

6. Exclude User with ‘^’ Character

7. Find Out who’s Looking What Files and Commands?

8. List all Network Connections

9. Search by PID

10. Kill all Activity of Particular User

log sources.list

cat /var/log/auth.log 

cat /etc/apt/sources.list

perl: warning: Setting locale failed. debian

$ sudo locale-gen
$ sudo dpkg-reconfigure locales

perl: warning: Setting locale failed.

perl: warning: Please check that your locale settings:

LANGUAGE = "en_HK:en",

LC_ALL = (unset),

LC_CTYPE = "UTF-8",

LANG = "en_HK.UTF-8"

    are supported and installed on your system.

perl: warning: Falling back to a fallback locale ("en_HK.UTF-8").

node.js install and hello world

curl -sL https://deb.nodesource.com/setup | sudo bash -

sudo apt-get install -y nodejs

apt-get install -y build-essential

example.js

var http = require('http');
http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello World\n');
}).listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');

result

% node example.js
Server running at http://127.0.0.1:1337/

create group, add user

groupadd groupname

gpasswd -a user1 groupname
gpasswd -a user1 groupname

add user to sudo group

sudo adduser username
sudo adduser username sudo