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"foo_and_bars".classify                      
# => "FooAndBar" #String
"foo_and_bars".classify.constantize  
# => "FooAndBar" #Class

# In Ruby, class names are constants, so you can do
str = "Thing" # => "Thing"
Kernel.const_get(str) # => Thing

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class Person    
    def initialize(name)
        @name = name
    end    
end

class Employee < Person
end

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To copy code from the terminal use

• Cntrl + Insert
• Rightclick + copy text

To paste code into the terminal use

• Shift + Insert
• Rightclick + p

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attr_accessor is used to create setter and getter methods for instance variables so that they can be accessed outside the class. initialize is the special method in ruby that gets called when an object is instantiated.

class Birthday
 attr_accessor :name
 
 def initialize age, gender
   @age = age
   self.gender = gender

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To get formatted results for select statements use \G as a suffix for the query.

select * from table_name \G;

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As we use object.class method in Ruby world, to check the class of a variable in Javascript, here is the snippet

var ss = "some string";
alert (typeof ss);  #=> string
alert (typeof pp);  #=> undefined

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In case you have trouble in accessing internet using your wired connection and while troubleshooting, if your network manager says that

"device is not managed"

open the terminal and follow the below steps to fix the issue.

sudo vim /etc/NetworkManager/NetworkManager.conf

change the line managed=false to managed=true

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To access remote machine using SSH

> ssh user@remote-host
> enter password when prompted

To get rid of entering password everytime you try to access, SSH keys has to be exchanged between local machine and remote server.

> ssh-keygen [Enter] [Enter] [Enter]

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grep -rnw 'directory' -e "text-to-search"

-r is recursive, -n is line number and -w stands match the whole word.

grep --include={*.c,*.h} -rnw 'directory' -e "pattern"

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gksudo nautilus

aletrnatively,

sudo nautilus