Another source link: http://www.gotealeaf.com/blog/how-to-install-ruby-on-rails-development-environment-for-linux

https://gorails.com/setup/ubuntu/14.04

sudo apt-get update
sudo apt-get install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev libcurl4-openssl-dev python-software-properties

cd
git clone git://github.com/sstephenson/rbenv.git .rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
exec $SHELL

git clone git://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build
echo 'export PATH="$HOME/.rbenv/plugins/ruby-build/bin:$PATH"' >> ~/.bashrc
exec $SHELL

rbenv install 2.1.3
rbenv global 2.1.3
ruby -v

The last step is to tell Rubygems not to install the documentation for each package locally

echo "gem: --no-ri --no-rdoc" > ~/.gemrc

git config --global color.ui true
git config --global user.name "Alfredo"
git config --global user.email "alfredo.roca.mas@gmail.com"
ssh-keygen -t rsa -C "alfredo.roca.mas@gmail.com"

The next step is to take the newly generated SSH key and add it to your Github account. You want to copy and paste the output of the following command and paste it here.

cat ~/.ssh/id_rsa.pub

Once you've done this, you can check and see if it worked:

ssh -T git@github.com

You should get a message like this:

Hi excid3! You've successfully authenticated, but GitHub does not provide shell access.

sudo add-apt-repository ppa:chris-lea/node.js
sudo apt-get update
sudo apt-get install nodejs
gem install rails

If you're using rbenv, you'll need to run the following command to make the rails executable available:

rbenv rehash

Now that you've installed Rails, you can run the rails -v command to make sure you have everything installed correctly:

rails -v
# Rails 4.1.8 o similar

For PostgreSQL, we're going to add a new repository to easily install a recent version of Postgres 9.3.

sudo sh -c "echo 'deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main' > /etc/apt/sources.list.d/pgdg.list"
wget --quiet -O - http://apt.postgresql.org/pub/repos/apt/ACCC4CF8.asc | sudo apt-key add -
sudo apt-get update
sudo apt-get install postgresql-common
sudo apt-get install postgresql-9.3 libpq-dev

The postgres installation doesn't setup a user for you, so you'll need to follow these steps to create a user with permission to create databases.

sudo -u postgres createuser alfredo -s

# If you would like to set a password for the user, you can do the following

sudo -u postgres psql
postgres=# \password alfredo

And now for the moment of truth. Let's create your first Rails application:

#### If you want to use Postgres
# Note that this will expect a postgres user with the same username
# as your app, you may need to edit config/database.yml to match the
# user you created earlier

rails new myapp -d postgresql

# Move into the application directory

cd myapp

# If you setup MySQL or Postgres with a username/password, modify the
# config/database.yml file to contain the username/password that you specified

# Create the database

rake db:create
rails server

http://stackoverflow.com/questions/16151018/npm-throws-error-without-sudo

It's safer to create a new group for node-users and add the required users to this group, further to set the ownership of node-dependant files/directories to this group.

# Create new group

sudo groupadd nodegrp 

# Add user to group (logname is a variable and gets replaced by the currently logged in user)

sudo usermod -a -G nodegrp `logname`

# Instant access to group without re-login

newgrp nodegrp

# Check group - nodegrp should be listed as well now

groups

# Change group of node_modules, node, npm to new group

sudo chgrp -R nodegrp /usr/lib/node_modules/
sudo chgrp -R nodegrp /usr/lib/nodejs
sudo chgrp nodegrp /usr/bin/node
sudo chgrp nodegrp /usr/bin/npm

# (You may want to change a couple of more files (like grunt etc) in your /usr/bin/ directory.)

Now you can easily install your modules as user

npm install -g generator-angular

Some modules (grunt, bower, yo etc.) will still need to be installed as root. This is because they create symlinks in /user/bin/.

basename=# SELECT * FROM tabla;

SHOW TABLES basename=# \d
SHOW DATABASES basename=# \l
SHOW COLUMNS basename=# \d table
DESCRIBE TABLE basename=# \d+ table
\du lista los usuarios de postgres y sus propiedades
createuser -P -s -d -r -e zabbix crea el usuario zabbix con privilegios de root
psql -h localhost -U zabbix zabbix entramos en Postgres, con el usuario zabbix a la base de datos zabbix

Conectar a base de datos # \c basename

Cómo revisar si PostgreSQL está funcionando: $ /etc/init.d/postgresql status Password:

==> pg_ctl: server is running (PID: 6171)

Salir # \q

development:

adapter: postgresql
encoding: unicode
database: myapp_development
pool: 5
username: alfredo
password: oderfla

test:

adapter: postgresql
encoding: unicode
database: myapp_test
pool: 5
username: alfredo
password: oderfla

$ rake db:create:all