Blocks

gistfile1.rb

# Example 1
def file_read(filename)
  file = File.new(filename,'r')
  yield file # file is the variable passed into the block (anything between do and end is a block) f is the variable used the access this in example 1 usage.
  file.close
end 

# Example 1 usage
file_read('temp.rb') do |f| # f is the file descriptor for accessing methods on the file 
  puts f.read # reads the whole file as a string puts is essentially println in java
end # File Closes here


# Example 2
File.open('temp.rb','r') do |f|
  puts f.read
end 


# Example 1 is my remake of Example 2 which is part of the ruby lang.

# The regex
puts data.gsub(/(.+)\n/){$1+"\t") # This subs all the lines with one or more chars(non empty lines) the {} takes the line and appends a tab
# Not the lines between the records don't get changed as they have zero characters before the new line.
# This is a classic technique in regex to use matching groups. $1 signifies the first matching group.