How to execute a Ruby script in Terminal?

Question

I've set everything up that I need on my Mac (Ruby, Rails, Homebrew, Git, etc), and I've even written a small program. Now, how do I execute it in Terminal? I wrote the program in Redcar and saved it as a .rb, but I don't know how to execute it through Terminal. I want to run the program and see if it actually works. How do I do this?

• ian: I don't know who voted down your very first question, but I think that's harsh so I've voted it back up. Good luck with everything, it all seems so confusing at first but persevere and before long it'll be second nature, and then you'll be helping out other people on here.
• Daniel: Fast forward to 2017 and now the OP has 2,555 points and over 100 badges. :)
• Hebron Watson: I love the positive energy, but we've proved the point. Agreed that our community needs to be supportive to newcomers and to anyone needing support to learn a new skill.

Answer 1

Just call: ruby your_program.rb

or

• start your program with #!/usr/bin/env ruby,
• make your file executable by running chmod +x your_program.rb
• and do ./your_program.rb some_param

• Tom Maxwell: When I call ruby your_program.rb, I get this: ruby: No such file or directory -- testapp.rb (LoadError)
• Joshua Cheek: @TomMaxwell When he says ruby your_program.rb, you are supposed to substitute 'your_program.rb' with whatever the name is of your program. In this case, based on your error message, it is probably supposed to be ruby testapp.rb. Though @Robin is correct in that you need to be in the same directory as the Ruby file.
• Robin: I think he did, otherwise the error message would not be about testapp.rb. But based on his other comments, he didn't know how to cd to his Desktop directory, so that must be it.
• LiangWang: how about if there're some require in .rb file?
• nstein: @Chris Page, I actually had this problem by using the first way. I changed mod as you suggested and it worked! Thanks a ton!

Answer 2

Open your terminal and open folder where file is saved.
Ex /home/User1/program/test.rb

1. Open terminal
2. cd /home/User1/program
3. ruby test.rb

format or test.rb

class Test 
 def initialize
 puts "I love India"
 end
end
# initialize object
Test.new

output

I love India

• DanielH: Class should be class (with a lower c). Otherwise it won't work.
• Rajkiran: Love the output 🇮🇳
• Adrian Gaile Singh: I love Philippines! haha

Answer 3

Assuming ruby interpreter is in your PATH (it should be), you simply run

ruby your_file.rb

• Tom Maxwell: That gives me an error message, so I'm guessing I did something wrong during setup. How do I do that?
• Tom Maxwell: ruby: No such file or directory -- testapp.rb (LoadError)
• Sergio Tulentsev: what's a testapp.rb? Are you in the same dir where it is?
• Tom Maxwell: I think what you said about the ruby interpreter being in my PATH is the issue. I probably didn't do something correctly; it took me a lot of messing around to get everything set up.
• Sergio Tulentsev: cd is a terminal command that changes current directory. For example, to go to a "Desktop" dir that is in your HOME_DIR, you'd have to do cd ~/Desktop.

Answer 4

To call ruby file use : ruby your_program.rb

To execute your ruby file as script:

1. start your program with #!/usr/bin/env ruby

2. run that script using ./your_program.rb param

3. If you are not able to execute this script check permissions for file.

• Priti Biyani: Generally to execute a script, you need to give execute permission. If that is not given, it would not work with above command. Check your permissions and then use the same command.

Answer 5

Just invoke ruby XXXXX.rb in terminal, if the interpreter is in your $PATH variable.

( this can hardly be a rails thing, until you have it running. )

Answer 6

For those not getting a solution for older answers, i simply put my file name as the very first line in my code.

like so

 #ruby_file_name_here.rb
 puts "hello world"

Answer 7

You can run ruby code just passing -e option

ruby -e 'x = Time.now; puts x;'

Output will be:

2022年06月22日 15:55:06 +0500

Answer 8

Although its too late to answer this question, but still for those guys who came here to see the solution of same problem just like me and didn't get a satisfactory answer on this page, The reason is that you don't have your file in the form of .rb extension. You most probably have it in simple text mode. Let me elaborate. Binding up the whole solution on the page, here you go (assuming you filename is abc.rb or at least you created abc):

Type in terminal window:

cd ~/to/the/program/location
ruby abc.rb

and you are done

If the following error occurs

ruby: No such file or directory -- abc.rb (LoadError)

Then go to the directory in which you have the abc file, rename it as abc.rb Close gedit and reopen the file abc.rb. Apply the same set of commands and success!

Answer 9

In case someone is trying to run a script in a RAILS environment, rails provide a runner to execute scripts in rails context via

rails runner my_script.rb

More details here: https://guides.rubyonrails.org/command_line.html#rails-runner

Answer 10

Open Terminal

cd to/the/program/location
ruby program.rb

or add #!/usr/bin/env ruby in the first of your program (script tell that this is executed using Ruby Interpreter)

Open Terminal

cd to/the/program/location
chmod 777 program.rb
./program.rb