How to read lines of a file in Ruby

📝 Title: How to Easily Read Lines of a File in Ruby

👋 Hey there, Ruby enthusiasts! Are you struggling to read lines from a file in Ruby? Don't worry, we've got your back! In this blog post, we'll tackle a common issue and provide you with easy, straightforward solutions. Let's dive right in! 💻📂

🤔 So, you've encountered a problem when reading files in Ruby. You noticed that when trying to read a file, the contents are all in one line. 😫 No worries, we'll help you overcome this obstacle. Let's take a look at the code snippet you provided:

line_num=0
File.open('xxx.txt').each do |line|
  print "#{line_num += 1} #{line}"
end

🧐 It seems like you're encountering this problem with a specific file. You mentioned that when you try to read a different file, the lines are printed separately. This tells us that the issue lies with the file itself, rather than the code you're using. Let's examine further.

💡 When reading files, Ruby makes assumptions about the line-ending characters used in the file. These assumptions can cause the contents to appear in one line if Ruby doesn't correctly interpret the line endings. To handle this situation properly, we suggest using the IO.foreach method instead of File.open. Here's a new solution for you:

line_num = 0
IO.foreach('xxx.txt', chomp: true) do |line|
  print "#{line_num += 1} #{line}"
end

🚀 Ta-da! By using IO.foreach with the chomp: true option, you're instructing Ruby to remove any line-ending characters from each line it reads. This way, you'll get each line separately, regardless of the line-ending characters used in the file. 🌟

🌈 But what if you need to read lines from standard input (stdin) and can't assume the line-ending character used in the file? We've got you covered! 🙌

🔑 To handle this scenario, you can use a combination of gets and chomp methods. Here's an example:

line_num = 0
loop do
  line = gets
  break if line.nil?

  print "#{line_num += 1} #{line.chomp}"
end

🏃‍♂️ In this solution, we're using a loop to continuously read lines from standard input (gets) until there are no more lines. The chomp method removes any line-ending characters, ensuring each line is printed separately.

🔊 Now that you've learned how to read lines from files in Ruby and handle various scenarios, it's time to put your knowledge into practice. 😎 Share your experience in the comments below and let us know if you found these solutions helpful!

🙌 Remember, Ruby is a versatile language, and understanding how to read lines from files is a crucial skill. By mastering this task, you'll be able to effortlessly process file contents and create amazing applications.

👋 Until next time, happy coding! 💻✨