In Ruby, you can read a file using the built-in File class. Here's an example of how you can read a file:
# open the file
file = File.open('filename.txt', 'r')
# read the contents of the file
file_contents = file.read
# close the file
file.close
# print the contents of the file
puts file_contents
In this example, we're opening a file named filename.txt in read mode ('r'). Then we read the contents of the file using the read method and assign it to the file_contents variable. Finally, we close the file using the close method.
Here's another example that demonstrates how to read a file line by line in Ruby:
# open the file
File.open('filename.txt', 'r') do |file|
# read the file line by line
file.each_line do |line|
# print each line to the console
puts line
end
end
In this example, we use the File.open method with a block to automatically close the file after we're done with it. We then use the each_line method to read the file line by line and print each line to the console.