install ruby and ruby on rails on ubuntu 12.04

In summary

• update your system
• install git, curl, rvm
• install required packages
• install rails
• done

Step by step

Update system

sudo apt-get update

Install git

sudo apt-get install git

Install curl

sudo apt-get install curl

Install rvm

curl -L get.rvm.io | bash -s stable

Reload to start using rvm

source ~/.rvm/scripts/rvm

or 

source /home//.rvm/scripts/rvm

Check required packages

rvm requirements

and then copy the install command from output, it should look like this

sudo apt-get -y install build-essential openssl libreadline6 libreadline6-dev zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev ncurses-dev automake libtool bison subversion

Install Javascript runtime

sudo apt-get install nodejs

Install ruby

rvm install 1.9.3

(1.9.3 is the newest version at the time of this writing)

Set ruby version to default

rvm use 1.9.3 --default

Install rails

gem install rails

Done

start your app and see it works! cheers!

references: http://blog.sudobits.com/2012/05/02/how-to-install-ruby-on-rails-in-ubuntu-12-04-lts/

ubuntu - install LAMP server with one click

tasksel is a good service for installing LAMP on ubuntu 12.04 and 11.10

sudo apt-get install tasksel

sudo tasksel

this can be used to install postgreSQL and many others

ubuntu - preventing apache and mysql from auto start when computer starts

• apache2 uses System V style init scripts. To disable it from boot:
  sudo update-rc.d -f apache2 remove
• However, mysql uses an Upstart job, to disable it, create an "override" file:
  echo "manual" | sudo tee /etc/init/mysql.override

To learn more about override files, see: The Upstart Cookbook

Use number_format() function in PHP

You can use the PHP function number_format to format a number in several ways, including choosing how many decimal points it will have, and choosing the 1000s, and decimal point dividers. It is phrased as number_format ( your_number , optional_decimals , optional_decimal_point, optional_1000_separator ) You can not specify just the decimal point or 1000 separator, if you specify one you need to specify both. When working with decimals, it will function like round () and put things at or over .5 up, and under .5 down.

    number_format (1234.567); //Returns the number 1,235 
    number_format (1234.567, 2); //Returns the number 1,234.57 
    number_format (1234.567, 2, ',', ' '); //Returns the number 1 234,57 
    number_format (1234.567, 1, 'a', 'b'); //Returns the number 1b234a6 

Problem with javascript replace() function

Suppose we have a string: "The horse kicks the stony horse". Using javascript replace() function, we want to replace 'horse' by 'cow'.

    str = "The horse kicks the stony horse";
    replaced_str = str.replace('horse', 'cow');

and the result of replaced_str is "The cow kicks the stony horse" ... surprise!

The replace() function replaced only the first string which was found and ignore others. What we should do?

Regex is a way to solve it, instead

    replaced_str = str.replace('horse', 'cow');

We use

    replaced_str = str.replace(/horse/g, 'cow');

and the replaced_str should be "The cow kicks the stone cow".

Install PHP on Windows, Linux, MacOS

This post is about how to install a ready-working PHP environment on different OS.

Personally, I prefer a full package to install one by one package. This mean, there're some pre-built solution for PHP, MySQL, Apache just install and run.

For Windows machine, download Appserv, install and got everything people want to start working with PHP.

MacOS, after a few days struggle with package installation, I found MAMP is acceptable.

Linux, here are a good guide

Moreover, you may want to build a virtual machine (CentOS for example) on Windows machine. Download and install PHP, mysql, apache on that centos, and then access it from your Windows machine. This will let you use eclipse on windows to modify the source on run on centos. It's good in some ways, especial to people who stick with windows but still want to use PHP on Linux.

Prepare the environment for PHP programming

This post aims to developer, who is familiar with programming but has less experiences with PHP. Here you can see what need to do to start working with PHP.

Operation system
PHP can be mostly installed in Windows (all version), Linux (all version), MacOS. As my observer, Linux gives the best performance and suitable for both junior and advance PHP programmer.

IDE
There're many IDE for PHP programming, most of them do the good job. I prefer PDT to others, because it's eclipse's plugin and support syntax highlight, indentation, good completion.

Aside from that, PDT is acceptable for HTML/CSS/Javascript editing.

What to do
Here comes the list of what need to do

• download and install Webserver, Apache  is good for all of us, but you may want to try Ngnix
• download and install PHP. It's vary from OS.
• download and install database system, MySQL  is good for start. Next time you may want to try some NoSQL
• config your webserver to support mod rewrite and install the necessarily library for connecting PHP to database server.

The last time
Create some project, find sample code, and start working. You'll learn a lot while dealing with real problem.