gistfile1.rbx

f = File.new("myfile.txt", "r") # open a file with read-mode

# ... do some stuff with the file, like read its content, ouput it on the screen or whatever

# finally: close it!
f.close


# or:

File.new("myfile.txt", "w") do |f|
  
  # now here you can do stuff with f (the file) same as above
  # only that you don't have to close the file manually, it gets done automatically once the block has ended.
  # the code for closing is inside the constructor of file and gets executed 
  #   a) if there is a block given => after the block has finished
  #   b) not at all, if no block is given (needs to be called manually)
end