# Using irb as a REPL **URL:** \ **Category:** Ruby\ **Created:** [November 20, 2007, 12:26am UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706 "2007-11-20T00:26:07Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 20, 2007, 12:26am UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/1 "2007-11-20T00:26:07Z")
Lisp programmers often use the REPL (similar to IRB) as a simple way to make an interactive interface to their app. I’d like to do the same thing with irb - that is, define my classes, and load irb in the context. I can get about half way there: require ‘irb’ IRB.start my\_class = MyClass.new(…) # I want this to be the context irb my\_class …works, but you have to type “quit” to load. Is there a better way to leverage IRB from within my code? What do the Ruby hackers say? (I know a lot have a Lisp background, and so wouldn’t want Ruby to not have a REPL shell…) ---
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 20, 2007, 12:35am UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/2 "2007-11-20T00:35:28Z")
On Nov 19, 6:21 pm, “S. Robert J.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > irb my\_class > > …works, but you have to type “quit” to load. Is there a better way > to leverage IRB from within my code? What do the Ruby hackers say? (I > know a lot have a Lisp background, and so wouldn’t want Ruby to not > have a REPL shell…) Another, similar problem with the above: irb my\_class conf.prompt\_mode = :SIMPLE # This line is ignored ---
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 20, 2007, 3:08am UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/3 "2007-11-20T03:08:32Z")
On 11/19/07, S. Robert J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > my\_class = MyClass.new(…) # I want this to be the context > > irb my\_class > > > > …works, but you have to type “quit” to load. Is there a better way > > to leverage IRB from within my code? What do the Ruby hackers say? (I > > know a lot have a Lisp background, and so wouldn’t want Ruby to not > > have a REPL shell…) > > Another, similar problem with the above: > irb my\_class > conf.prompt\_mode = :SIMPLE # This line is ignored hmmm, I’ve also had some problems trying to add a command interface to some code. I found trying to bend IRB to fit the needs seems to be trickier than just coding up a solution in readline directly. Is that really the best solution? Cameron ---
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 20, 2007, 3:36am UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/4 "2007-11-20T03:36:01Z")
On Nov 19, 9:07 pm, Cameron McBride [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > hmmm, I’ve also had some problems trying to add a command interface to > some code. I found trying to bend IRB to fit the needs seems to be > trickier than just coding up a solution in readline directly. Is that > really the best solution? > > Cameron Then you miss out on the full power of Ruby in your interface! The beauty of using a REPL or IRB is that you have an easy command line interface, with automatic scripting when you need it, expandable to the full power of the host language as needed. ---
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 20, 2007, 3:48am UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/5 "2007-11-20T03:48:18Z")
On 11/19/07, S. Robert J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > The beauty of using a REPL or IRB is that you have an easy command > line interface, with automatic scripting when you need it, expandable > to the full power of the host language as needed. Sorry, I wasn’t clear. I’m talking about building a ruby library and then the CLI with readline does a stateful eval. Problem is that it reimplements functionality that already exists in IRB. Cameron ---
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 20, 2007, 4:43am UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/6 "2007-11-20T04:43:14Z")
On Tue, Nov 20, 2007 at 08:25:00AM +0900, S. Robert J. wrote: > Lisp programmers often use the REPL (similar to IRB) as a simple way > to make an interactive interface to their app. I’d like to do the > same thing with irb - that is, define my classes, and load irb in the > context. There’s an example of this in Shoes: [http://code.whytheluckystiff.net/svn/shoes/trunk/samples/irb.rb](http://code.whytheluckystiff.net/svn/shoes/trunk/samples/irb.rb) The MimickIRB class just wraps IRB’s RubyLex class in a very simple REPL. I don’t know if this is exactly what you’re looking for (since it doesn’t do debugging, .irbrc, or frames) but it’s nice if you want to start your own from nothing. \_why ---
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 20, 2007, 9:08pm UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/7 "2007-11-20T21:08:35Z")
On 11/19/07, S. Robert J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Lisp programmers often use the REPL (similar to IRB) as a simple way > to make an interactive interface to their app. I’d like to do the > same thing with irb - that is, define my classes, and load irb in the > context. There’s one very simple way to do this. Do gem install aws-s3 And have a look at s3sh in the bin dir. It’s basically just a shell script. It just aims regular old IRB at a setup file which establishes some relevant variables and loads some relevant modules. Rails console does nearly exactly the same thing - all it really adds in is more libraries and some command-line args with optparse. – Giles B. Podcast: [http://hollywoodgrit.blogspot.com](http://hollywoodgrit.blogspot.com) Blog: [http://gilesbowkett.blogspot.com](http://gilesbowkett.blogspot.com) Portfolio: [http://www.gilesgoatboy.org](http://www.gilesgoatboy.org) Tumblelog: [http://giles.tumblr.com](http://giles.tumblr.com) ---
**Author:** ![robertjames](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e9c0ed/32.png) [@robertjames](https://www.ruby-forum.com/u/robertjames)\ **Post date:** [November 29, 2007, 10:46pm UTC](https://www.ruby-forum.com/t/using-irb-as-a-repl/120706/8 "2007-11-29T22:46:39Z")
S. Robert J. wrote: > irb my\_class > > …works, but you have to type “quit” to load. Is there a better way > to leverage IRB from within my code? What do the Ruby hackers say? (I > know a lot have a Lisp background, and so wouldn’t want Ruby to not > have a REPL shell…) This might help: [http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/244139](http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/244139)