Running scripts with ruby command - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to run a Ruby script named 'hello.rb' from the command line.

Ruby

ruby [1]

Drag options to blanks, or click blank then click option'

Ascript.py

Brun.rb

Cmain.js

Dhello.rb

Attempts:

3 left

💡 Hint

Common Mistakes

Using a filename with the wrong extension like '.py' or '.js'.

Forgetting to include the script filename after 'ruby'.

To run a Ruby script, use the 'ruby' command followed by the script filename, like 'ruby hello.rb'.

2fill in blank

medium

Complete the command to run a Ruby script called 'calculator.rb' located in the current directory.

Ruby

ruby [1]

Drag options to blanks, or click blank then click option'

Aapp.js

Bscript.py

Ccalculator.rb

Dprogram.txt

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to run a non-Ruby file.

Typing the wrong filename.

You run the Ruby script by typing 'ruby' followed by the script's filename, here 'calculator.rb'.

3fill in blank

hard

Fix the error in the command to run 'test_script.rb' by completing the missing part.

Ruby

ruby [1]

Drag options to blanks, or click blank then click option'

Atest_script.txt

Btest_script.rb

Ctest_script.js

Dtest_script.py

Attempts:

3 left

💡 Hint

Common Mistakes

Using a filename with a wrong extension.

Typing a filename that does not exist.

The Ruby interpreter requires the script filename with the '.rb' extension to run it correctly.

4fill in blank

hard

Fill both blanks to run a Ruby script named 'server.rb' located in a folder called 'app'.

Ruby

ruby [1]/[2]

Drag options to blanks, or click blank then click option'

Aapp

Bserver.rb

Cbin

Dmain.rb

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping folder and filename positions.

Using the wrong folder or filename.

To run a script in a folder, use 'ruby foldername/filename.rb', here 'ruby app/server.rb'.

5fill in blank

hard

Fill both blanks to run a Ruby script named 'app.rb' inside the 'src' folder with verbose mode enabled.

Ruby

ruby [1] [2]

Drag options to blanks, or click blank then click option'

A-v

Bsrc/app.rb

C--verbose

D-h

Attempts:

3 left

💡 Hint

Common Mistakes

Placing the script path before the flag.

Using incorrect flags like '-v' or '-h'.

To run a script with verbose mode, use 'ruby --verbose src/app.rb'.

Practice

1. What does the ruby command do when used in the terminal?

easy

A. It runs a Ruby script saved in a file.

B. It compiles Ruby code into an executable.

C. It opens the Ruby interactive console.

D. It installs Ruby gems automatically.

Solution

1. Step 1: Understand the purpose of the ruby command

   The ruby command is used to run Ruby scripts saved in files from the terminal.

2. Step 2: Differentiate from other Ruby tools

   It does not compile code, open the console, or install gems automatically.

3. Final Answer:

   It runs a Ruby script saved in a file. -> Option A

4. Quick Check:

   ruby command runs scripts = A [OK]

Hint: ruby command runs saved scripts, not compilers or consoles [OK]

Common Mistakes:

• Confusing ruby command with irb (interactive console)
• Thinking ruby compiles code to executables
• Assuming ruby installs gems automatically

2. Which of the following is the correct way to run a Ruby script named hello.rb from the terminal?

easy

A. run hello.rb

B. start ruby hello.rb

C. execute hello.rb

D. ruby hello.rb

Solution

1. Step 1: Identify the correct command syntax

   The correct syntax to run a Ruby script is ruby filename.rb.

2. Step 2: Check each option

   Only ruby hello.rb matches the correct syntax.

3. Final Answer:

   ruby hello.rb -> Option D

4. Quick Check:

   Use ruby + filename.rb to run scripts [OK]

Hint: Use 'ruby filename.rb' to run scripts in terminal [OK]

Common Mistakes:

• Using 'run' or 'execute' commands which don't exist
• Adding extra words like 'start' before ruby
• Forgetting to include the .rb extension

3. Given a file greet.rb with the following content:

puts "Hello, Ruby!"

What will be the output when you run ruby greet.rb in the terminal?

medium

A. Hello, Ruby!

B. puts "Hello, Ruby!"

C. SyntaxError

D. No output

Solution

1. Step 1: Understand the Ruby code

   The code uses puts to print the string "Hello, Ruby!" to the terminal.

2. Step 2: Predict the output of running the script

   Running ruby greet.rb executes the code and prints the string.

3. Final Answer:

   Hello, Ruby! -> Option A

4. Quick Check:

   puts prints string output = C [OK]

Hint: puts prints text exactly when script runs [OK]

Common Mistakes:

• Thinking puts prints the code itself
• Expecting no output from puts
• Confusing syntax errors with correct code

4. You try to run a Ruby script with ruby myscript.rb but get an error: ruby: command not found. What is the most likely cause?

medium

A. The script file myscript.rb has a syntax error.

B. Ruby is not installed or not in your system's PATH.

C. You forgot to save the script file.

D. You need to add ./ before the filename.

Solution

1. Step 1: Analyze the error message

   The error ruby: command not found means the terminal cannot find the ruby program.

2. Step 2: Identify the cause

   This usually means Ruby is not installed or its location is not in the system PATH environment variable.

3. Final Answer:

   Ruby is not installed or not in your system's PATH. -> Option B

4. Quick Check:

   Command not found means Ruby missing or PATH issue [OK]

Hint: Command not found means Ruby missing or PATH issue [OK]

Common Mistakes:

• Assuming syntax error causes command not found
• Thinking file must be saved to fix this error
• Adding ./ before filename only works for executables, not ruby command

5. You have two Ruby scripts in the same folder: first.rb and second.rb. You want to run second.rb but accidentally type ruby first.rb. How can you avoid this mistake when running scripts?

hard

A. Use ruby run second.rb to specify the script.

B. Rename the files to have different extensions.

C. Always check your current folder and type the exact filename with extension.

D. Run scripts without typing the filename; Ruby will pick the right one.

Solution

1. Step 1: Understand the cause of the mistake

   Typing the wrong filename runs the wrong script because the command requires exact filenames.

2. Step 2: Find the best practice to avoid errors

   Always verify your current folder and type the exact filename with extension to run the correct script.

3. Final Answer:

   Always check your current folder and type the exact filename with extension. -> Option C

4. Quick Check:

   Exact filename avoids running wrong script [OK]

Hint: Double-check filename and folder before running script [OK]

Common Mistakes:

• Thinking Ruby auto-selects the right script
• Trying to run scripts without filenames
• Using incorrect commands like 'ruby run'