Remove all Ruby Gems

To remove all gems from your system, this should work.

gem list | cut -d" " -f1 | xargs gem uninstall -aIx

On JRuby following works

gem list --no-versions |  while read x; do sudo gem uninstall $x -a; done

Many a times you may run in to situation where you simply want to clean up all the gems installed. I found this article very helpful. Above command is copied from their. You can read detail on the site.

Git Reference card

Git create remote branch

To create a local branch

git branch branch_name

To switch/checkout local branch

git checkout branch_name

You can combine above two in one step instead

git checkout -b your_branch

Create remote branch (so that other co-workers/programmers/whoever can pull)

git push -u origin your_branch

Others can pull this by

git checkout origin/your_branch

View diff in GIT

What you will commit

git diff

diff between two branch

git diff master..branch_1

diff since last commit

git diff HEAD

This entry is a note to self for being amnesiac

.

Disqus(ted)

Great added Disqus to blog. Looks like I lost all old comments (of whatever few I had).

Using git stash

A very useful feature in git is git stash, a write up on it GIT: Using the stash

Install ruby using RVM

This is note to self, for installing ruby 1.8.7 using RVM. Other versions can be installed in same way "mostly". Just replace the version 1.8.7 with version intended

Verbose documentation about RVM installtion can be found at https://rvm.beginrescueend.com/rvm/install/

bash < <(curl -s https://rvm.beginrescueend.com/install/rvm)
echo '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function' >>

add above line in ~/.bashrc file in the end

rvm package install zlib
rvm package install openssl
rvm install 1.8.7--with-openssl-dir=$HOME/.rvm/usr
rvm use 1.8.7 --default

zlib and openssl is required in many cases.

Sinatra: memcached as session store

A simple route for using memcached as session store.

require 'rubygems'
require 'sinatra'

use Rack::Session::Memcache, :memcache_server => 'localhost:11211', :expire_after => 3600, :namespace => "sinatra.chandankumar.com"

get "/" do
"value = " << session[:value].inspect
end

get "/set" do
session[:value] = params[:value].inspect
redirect "/"
end

This would enable you to spawn multiple instances of (same) Sinatra app while sharing session store to achieve non sticky session. Helps scaling the front end.

Sinatra Ajax File Upload

Valums script at http://valums.com/ajax-upload/ works like a charm in sinatra route you would require something like

  get :upload do
    render "/test/upload", :layout => false
  end
  post :upload do
    logger.debug params
    newf = File.open("public/post.jpg", "wb")
    newf.write(request.body.read)
    '{success:true}'
  end