How to Save an IRB Session

The Interactive Ruby Shell (IRB) is a command-line program that allows developers to type a Ruby program with immediate interpretation and execution of their commands. This allows the developer to experiment with the output of different functions in real time, step through output line by line to assist with debugging, and create session files that allow the application written in IRB to be invoked or edited later by the user or system script. You can edit your IRB initialization script to have it automatically record each session to a file.

Instructions

1. Open the "Start" menu and type "%AppData%" in the search bar. Press "Enter."

2. Double-click "Ruby" and then double-click ".irbrc."

3. Open the file in Notepad by selecting it from the default applications list that appears on the screen.

4. Add the following lines of code to the end of the file:

   module IRB

   def IRB.buffer; @log; end

   @log = ""

   class WorkSpace

   alias backup_evaluate evaluate

   def evaluate(context, statements, file = __FILE__, line = __LINE__)

   result = backup_evaluate(context, statements, file, line)

   if /IRB\.buffer/.match(statements)

   IRB.buffer << "#{statements.chomp}\n"

   else

   IRB.buffer << "#{statements.chomp} #=> #{result.inspect}\n"

   end

   result

   end

   end

   end

5. Save the file by clicking "File," then "Save." When you begin a new IRB session, the file will be automatically saved in a file called "IRB.buffer" in the directory you launched your Ruby application from.

References

• "The Ruby Programming Language"; David Flanagan and Yukihiro Matsumoto; 2008