Installing a Crontab File

What is cron?

Crontab is a simple text file that holds a list of commands that are to be run at specified times.Cron is a that executes shell commands periodically on a given schedule. Cron is driven by a crontab, a configuration file that holds details of what commands are to be run along with a timetable of when to run them.

Description:

crontab -e [Edits a copy of the user's crontab file]

crontab -r [Remove the user's crontab files]

crontab -l [Lists the user's crontab file]

Crontab syntax:

A crontab file has six fields for specifying minute, hour, day of month, month, day of week and the command to be run at that interval. See below:

*     *     *     *     *  command to be executed
-     -     -     -     -
|     |     |     |     |
|     |     |     |     +----- day of week (0 - 6) (Sunday=0)
|     |     |     +------- month (1 - 12)
|     |     +--------- day of month (1 - 31)
|     +----------- hour (0 - 23)
+------------- min (0 - 59)

Any line beginning with a ``#'' is a comment and is ignored.

Crontab examples:

* * * * *  #Runs every minute
*/2 * * * *  #Runs every 2 minutes
35 * * * *  #Runs at 35 minutes past the hour
30 5 * * *  #Runs at 5:30 am every day
45 18 * * *  #Runs at 6:45 pm every day
00 3 * * 0  #Runs at 3:00 am every Sunday
00 2 * * 6  #Runs at 2:00 am every Satuday
00 1 * * Sun  #Runs at 1:00 am every Sunday
30 5 1 * *  #Runs at 5:30 am on the first day of every month
00 0-23/2 03 08 *  #Runs every other hour on the 3rd of August


There are also special strings that can be used:
@reboot  #Runs at boot
@yearly  #Runs once a year [0 0 1 1 *]
@annually  #Runs once a year [0 0 1 1 *]
@monthly  #Runs once a month [0 0 1 * *]
@weekly  #Runs once a week [0 0 * * 0]
@daily  #Runs once a day [0 0 * * *]
@midnight  #Runs once a day [0 0 * * *]
@hourly  #Runs once an hour [0 * * * *]

RailRoad (Ruby on Rails diagrams generator)

What is RailRoad?

RailRoad is a class diagrams generator for Ruby on Rails applications. It's a Ruby script that loads the application classes and analyzes its properties (attributes, methods) and relationships (inheritance, model associations like has_many, etc.) The output is a graph description in the DOT language, suitable to be handled with tools like Graphviz.

RailRoad can produce:

• Model diagrams, showing both inheritance hierarchy and models associations. You can choose to show the model "content columns" and its types.
• Controller diagrams, showing inheritance hierarchy. You can include the controllers' methods, grouped by its visibility (public, protected, private.)
• State machine diagramas (for use with the "acts_as_state_machine" plugin.)

Download RailRoad

If you're using gem, you can install RailRoad by issuing:

gem install railroad

Usage

Run RailRoad on the Rails application's root directory. You can redirect its output to a .dot file or pipe it to the dot or neato utilities to produce a graphic. Model diagrams are intended to be processed using dot and controller diagrams are best processed using neato.

railroad [options] command

Common options

• -b, --brief
  Generate compact diagram (no attributes nor methods)
• -e, --exclude file1[,fileN]
  Exclude given files
• -i, --inheritance
  Include inheritance relations
• -l, --label
  Add a label with diagram information (type, date, migration, version)
• -o, --output FILE
  Write diagram to file FILE
• -r, --root PATH
  Set PATH as the application root
• -v, --verbose
  Enable verbose output (produce messages to STDOUT)

Models diagram options

• -a, --all
  Include all models (not only ActiveRecord::Base derived)
• --hide-magic
  Hide magic field names
• --hide-types
  Hide attributes type
• -j, --join
  Concentrate edges
• -m, --modules
  Include modules
• -p, --plugins-models
  Include plugins models
• -t, --transitive
  Include transitive associations (through inheritance)

Controllers diagram options

• --hide-public
  Hide public methods
• --hide-protected
  Hide protected methods
• --hide-private
  Hide private methods

Other options

• -h, --help
  Show this message
• --version
  Show version and copyright

Commands

(You must supply one of these)

• -M, --models
  Generate models diagram
• -C, --controllers
  Generate controllers diagram
• -A, --aasm
  Generate "acts as state machine" diagram

Examples

• railroad -o models.dot -M
  Produces a models diagram to the file 'models.dot'
• railroad -a -i -o full_models.dot -M
  Models diagram with all classes showing inheritance relations
• railroad -M | dot -Tsvg > models.svg
  Model diagram in SVG format
• railroad -C | neato -Tpng > controllers.png
  Controller diagram in PNG format
• railroad -h
  Shows usage help

Validating the Credit Card, Without Processing Credit Card.

# THIS MODULE IS USED TO CHECK FROM http://www.trynt.com/creditcard-validation-api
# API TO CHECK WHETHER CREDIT CARD NUMBER IS NOT A DUMMY CARD NUMBER.
require 'net/http'
require 'uri'
require 'rexml/document'

module CreditCardVarification

include REXML

def is_credit_card_valid?(credit_card_no, year, month)
begin

dummy_card = %w(371449635398431 378734493671000 5610591081018250 30569309025904 38520000023237 6011111111111117 6011000990139424
3530111333300000 3566002020360505 5555555555554444 5105105105105100 4111111111111111 4012888888881881 4222222222222 76009244561
5019717010103742 6331101999990016)

action = get_body_from_url(credit_card_no, year, month)

if defined? Document.new(action).elements['Trynt/Credit-Card-Validation/Result'].text

result = Document.new(action).elements['Trynt/Credit-Card-Validation/Result'].text

unless result.nil?
if result.eql?("Appears Valid") && !dummy_card.include?credit_card_no.to_s)
return true
end
end
end
return false
rescue
return false
end
end

def get_body_from_url(credit_card_no, year, month)
url = "http://www.trynt.com/credit-card-validation-api/v1/?cc=#{credit_card_no}&y=#{year}&m=#{month}"
url = URI.parse(url)
res = Net::HTTP.get_response(url)
return res.body
end
end

Using Thread to store session variable

# THE BELOW MENTIONED FUNCTION WILL BE USED TO STORE THE SESSION VALUE SO THAT SESSION VARIABLES CAN BE USED IN MODEL...

module UserInfo
def get_current_user_in_model
Thread.current[:user]
end

def self.get_current_user_in_model=(user)
Thread.current[:user] = user
end
end

Insert At Cursor -- Javascript

function insertAtCursor(myField, myValue) {

//IE support

if (document.selection) {

myField.focus();

sel = document.selection.createRange();

sel.text = myValue;

}

//MOZILLA/NETSCAPE support

else if (myField.selectionStart || myField.selectionStart == '0') {

var startPos = myField.selectionStart;

var endPos = myField.selectionEnd;

myField.value = myField.value.substring(0, startPos)

+ myValue

+ myField.value.substring(endPos, myField.value.length);

} else {

myField.value += myValue;

}

}
// calling the function

insertAtCursor(document.formName.fieldName, 'this value');

Different ways of Validating Date of Birth in Model

def validate
if (date_of_birth.month==2 && date_of_birth.month.day > 29)
errors.add(:birthdate, "Invalida date")
end
end

OR

validates_each :date_of_birth do |record, attr, value|
record.errors.add attr, "is not a valid date. You must be at least 18 years old to sign in." if value.blank?
end

OR

def validate
if date_of_birth.month.blank? || date_of_birth.day.blank? || date_of_birth.year.blank?
errors.add_to_base "day, month and year cannot be blank."
end
end

Validates_presence_of : customise field name

validates_presence_of :id_country, :message => "Country can't be blank"

class Adresse < ActiveRecord::Base

HUMANIZED_COLLUMNS = {:id_country => "Country"}

def self.human_attribute_name(attribute)
HUMANIZED_COLLUMNS[attribute.to_sym] || super
end
end