mozamimy

require "resolv"

class Model < ActiveRecord::Base
  validates :ip_address, format: { with: Resolv::IPv4::Regex }
  validates :mac_address, format: { with: /\A([0-9A-F]{2}[-:]){5}([0-9A-F]{2})\z/ }
end

jensendarren

require 'fileutils'

# __FILE__ keyword in ruby
puts "The current ruby file being executed is #{__FILE__}"

# Gets the directory name of the file being executed
current_directory = File.dirname(__FILE__)
puts "The current directory is #{current_directory}"

# expands to reveal the pwd (Present working directory)

tuxfight3r

Bash Shortcuts

Moving

command	description
ctrl + a	Goto BEGINNING of command line

mycodeschool

/* Deleting a node from Binary search tree */
#include<iostream>
using namespace std;
struct Node {
	int data;
	struct Node *left;
	struct Node *right;
};
//Function to find minimum in a tree. 
Node* FindMin(Node* root)

Uradamus

function shuffle(tbl)
  for i = #tbl, 2, -1 do
    local j = math.random(i)
    tbl[i], tbl[j] = tbl[j], tbl[i]
  end
  return tbl
end

Integralist

Lambda: standard

# Creating a lambda
l = lambda { |name| "Hi #{name}!" }

# Executing the lambda
l.call("foo") # => Hi foo!

SauloSilva

// without callback
Array.prototype.eachSlice = function (size){
  this.arr = []
  for (var i = 0, l = this.length; i < l; i += size){
    this.arr.push(this.slice(i, i + size))
  }
  return this.arr
};

[1, 2, 3, 4, 5, 6].eachSlice(2)

emad-elsaid

#!/usr/bin/env ruby
require 'pdf/reader' # gem install pdf-reader

# credits to :
# 	https://github.com/yob/pdf-reader/blob/master/examples/text.rb
# usage example: 
# 	ruby pdf2txt.rb /path-to-file/file1.pdf [/path-to-file/file2.pdf..]
ARGV.each do |filename|

	PDF::Reader.open(filename) do |reader|

miguelmota

How to set up multiple accounts with Mutt E-mail Client

Thanks to this article by Christoph Berg

Instructions

Directories and files

~/

cosimo

#!/bin/bash
#
# Example of how to parse short/long options with 'getopt'
#

OPTS=`getopt -o vhns: --long verbose,dry-run,help,stack-size: -n 'parse-options' -- "$@"`

if [ $? != 0 ] ; then echo "Failed parsing options." >&2 ; exit 1 ; fi

echo "$OPTS"