Create, write and read a file and also print the first line of a file in ruby

Create a file: Open a file in write mode

ruby-1.9.2-p290 :058 > f = File.open(“my_file.txt”, “w”)
=>

Write something to that file

ruby-1.9.2-p290 :059 > f.write(“This is the first line of my file\n”)
=> 34

Close the file

ruby-1.9.2-p290 :060 > f.close
=> nil

Open the file for reading

ruby-1.9.2-p290 :061 > f = File.open(“my_file.txt”, “r”)
ruby-1.9.2-p290 :062 > f.read
=> “This is the first line of my file.\n”

Print the first line of a file

ruby-1.9.2-p290 :063 > lines = IO.readlines(“my_file.txt”)
ruby-1.9.2-p290 :063 > puts lines.first
This is the first line of my file.

A useful link about ruby File manupulation is given below