# Calling Irb from inside an application **URL:** \ **Category:** ruby-talk\ **Created:** [25 December 2007 13:08 UTC](https://rubytalk.org/t/calling-irb-from-inside-an-application/43281 "2007-12-25T13:08:41Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Bertram\_Scharpf](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@Bertram\_Scharpf](https://rubytalk.org/u/Bertram_Scharpf)\ **Post date:** [25 December 2007 13:08 UTC](https://rubytalk.org/t/calling-irb-from-inside-an-application/43281/1 "2007-12-25T13:08:41Z")
Hi, this may be easy to anwer but it is difficult to google for. While developping I would like to play around with objects from time to time. Just like this:     irb(main):001:0\> class C ; def f ; "F" ; end ; end     =\> nil     irb(main):002:0\> irb C.new     irb#1(#\):001:0\> f     =\> "F"     irb#1(#\):002:0\> In common my classes are not so easy to type in. So, I would like to call Irb from somewhere inside the application as I do here:     ----\>-call\_irb.rb---------------     #!/usr/bin/ruby     class C       def f         "F"       end     end     if $0 == \_\_FILE\_\_ then       require "irb"       $c = C.new       IRB.start     end     ----\<--------------------------- and then     user@host $ ./call\_irb.rb     irb(main):001:0\> irb $c     irb#1(#\):001:0\> f     =\> "F"     irb#1(#\):002:0\> Is there a way how I can call C.new's Irb directly without doing the long-winded definition of a global variable first? I already examined the irb sources but this seems to be well-hidden to me. Thanks in advance and Merry Christmas, Bertram > **···** > > -- > Bertram Scharpf > Stuttgart, Deutschland/Germany > [http://www.bertram-scharpf.de](http://www.bertram-scharpf.de) ---
**Author:** ![Stefano\_Crocco](https://avatars.discourse-cdn.com/v4/letter/s/5f9b8f/32.png) [@Stefano\_Crocco](https://rubytalk.org/u/Stefano_Crocco)\ **Post date:** [25 December 2007 13:26 UTC](https://rubytalk.org/t/calling-irb-from-inside-an-application/43281/2 "2007-12-25T13:26:10Z")
Alle martedì 25 dicembre 2007, Bertram Scharpf ha scritto: > Hi, > > this may be easy to anwer but it is difficult to google for. > > While developping I would like to play around with objects from > time to time. Just like this: > >     irb(main):001:0\> class C ; def f ; "F" ; end ; end >     =\> nil >     irb(main):002:0\> irb C.new >     irb#1(#\):001:0\> f >     =\> "F" >     irb#1(#\):002:0\> > > In common my classes are not so easy to type in. So, I would like > to call Irb from somewhere inside the application as I do here: > >     ----\>-call\_irb.rb--------------- >     #!/usr/bin/ruby > >     class C >       def f >         "F" >       end >     end > >     if $0 == \_\_FILE\_\_ then >       require "irb" >       $c = C.new >       IRB.start >     end >     ----\<--------------------------- > > and then > >     user@host $ ./call\_irb.rb >     irb(main):001:0\> irb $c >     irb#1(#\):001:0\> f >     =\> "F" >     irb#1(#\):002:0\> > > Is there a way how I can call C.new's Irb directly without doing > the long-winded definition of a global variable first? I already > examined the irb sources but this seems to be well-hidden to me. > > Thanks in advance and Merry Christmas, > > Bertram Not a direct answer to your question, but can't you load the file with the definition of the class in irb? Stefano ---
**Author:** ![Ryan\_Davis1](https://yyz1.discourse-cdn.com/flex029/user_avatar/rubytalk.org/ryan_davis1/32/1848_2.png) [@Ryan\_Davis1](https://rubytalk.org/u/Ryan_Davis1)\ **Post date:** [25 December 2007 20:16 UTC](https://rubytalk.org/t/calling-irb-from-inside-an-application/43281/3 "2007-12-25T20:16:03Z")
> In common my classes are not so easy to type in. So, I would like > to call Irb from somewhere inside the application as I do here: > >    if $0 == \_\_FILE\_\_ then >      require "irb" >      $c = C.new >      IRB.start >    end I'm a bit confused. Your subject line IS handled by this code. Indeed, this is what I grabbed from some of my code when I read the subject line:    def explore      Object.const\_set :"G", self      require 'irb'      puts "Your grammar is in the constant G"      IRB.start(\_\_FILE\_\_)    end So, what is the actual subject of this question? It doesn't seem to be "long-windedness" (below) either. > and then > >    user@host $ ./call\_irb.rb >    irb(main):001:0\> irb $c >    irb#1(#\):001:0\> f >    =\> "F" >    irb#1(#\):002:0\> > > Is there a way how I can call C.new's Irb directly without doing > the long-winded definition of a global variable first? I already > examined the irb sources but this seems to be well-hidden to me. I'm confused and havet o assume the question is a bit vague. How is "$c = " long winded? What do you actually want to know? > **···** > > On Dec 25, 2007, at 05:08 , Bertram Scharpf wrote: ---
**Author:** ![James\_Tucker](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@James\_Tucker](https://rubytalk.org/u/James_Tucker)\ **Post date:** [25 December 2007 14:01 UTC](https://rubytalk.org/t/calling-irb-from-inside-an-application/43281/4 "2007-12-25T14:01:54Z")
Merry christmas! This was mercilessly stolen and adapted from a post on Errs blog (only google has the answer ;): require 'irb' module IRB    def self.start\_session(binding)      IRB.setup(nil)      workspace = WorkSpace.new(binding)      if @CONF[:SCRIPT]        irb = Irb.new(workspace, @CONF[:SCRIPT])      else        irb = Irb.new(workspace)      end      @CONF[:IRB\_RC].call(irb.context) if @CONF[:IRB\_RC]      @CONF[:MAIN\_CONTEXT] = irb.context      trap("SIGINT") do        irb.signal\_handle      end      catch(:IRB\_EXIT) do        irb.eval\_input      end    end end def meths(o); puts (o.methods - Class.new.methods).join("\n"); end def dROP! b   old\_args = ARGV   ARGV.size.times { ARGV.shift }   if defined? IRBHelper     foo = Class.new     foo.instance\_eval do       include IRBHelper     end     puts "Helper Methods: #{(foo.new.methods - Class.new.methods).sort.join(', ')}"     include IRBHelper   end   IRB.start\_session b   old\_args.each { |a| ARGV \<\< a } end > **···** > > On 25 Dec 2007, at 13:26, Stefano Crocco wrote: > > > Alle martedì 25 dicembre 2007, Bertram Scharpf ha scritto: > > > > > Hi, > > > > > > this may be easy to anwer but it is difficult to google for. > > > > > > While developping I would like to play around with objects from > > > time to time. Just like this: > > > > > >    irb(main):001:0\> class C ; def f ; "F" ; end ; end > > >    =\> nil > > >    irb(main):002:0\> irb C.new > > >    irb#1(#\):001:0\> f > > >    =\> "F" > > >    irb#1(#\):002:0\> > > > > > > In common my classes are not so easy to type in. So, I would like > > > to call Irb from somewhere inside the application as I do here: > > > > > >    ----\>-call\_irb.rb--------------- > > >    #!/usr/bin/ruby > > > > > >    class C > > >      def f > > >        "F" > > >      end > > >    end > > > > > >    if $0 == \_\_FILE\_\_ then > > >      require "irb" > > >      $c = C.new > > >      IRB.start > > >    end > > >    ----\<--------------------------- > > > > > > and then > > > > > >    user@host $ ./call\_irb.rb > > >    irb(main):001:0\> irb $c > > >    irb#1(#\):001:0\> f > > >    =\> "F" > > >    irb#1(#\):002:0\> > > > > > > Is there a way how I can call C.new's Irb directly without doing > > > the long-winded definition of a global variable first? I already > > > examined the irb sources but this seems to be well-hidden to me. > > > > > > Thanks in advance and Merry Christmas, > > > > > > Bertram > > > > Not a direct answer to your question, but can't you load the file with the > > definition of the class in irb? > > > > Stefano ---
**Author:** ![Bertram\_Scharpf](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@Bertram\_Scharpf](https://rubytalk.org/u/Bertram_Scharpf)\ **Post date:** [25 December 2007 23:54 UTC](https://rubytalk.org/t/calling-irb-from-inside-an-application/43281/5 "2007-12-25T23:54:37Z")
Hi, > **···** > > Am Mittwoch, 26. Dez 2007, 05:16:03 +0900 schrieb Ryan Davis: > > > On Dec 25, 2007, at 05:08 , Bertram Scharpf wrote: > > > > > Is there a way how I can call C.new's Irb directly without doing > > > the long-winded definition of a global variable first? I already > > > examined the irb sources but this seems to be well-hidden to me. > > > > I'm confused and havet o assume the question is a bit vague. How is "$c = " > > long winded? What do you actually want to know? > > I wanted to know how to do it without having to type in the same > constant or global variable name every time. > > Bertram > > -- > Bertram Scharpf > Stuttgart, Deutschland/Germany > [http://www.bertram-scharpf.de](http://www.bertram-scharpf.de) ---
**Author:** ![Bertram\_Scharpf](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@Bertram\_Scharpf](https://rubytalk.org/u/Bertram_Scharpf)\ **Post date:** [25 December 2007 23:48 UTC](https://rubytalk.org/t/calling-irb-from-inside-an-application/43281/6 "2007-12-25T23:48:12Z")
Hi James, > **···** > > Am Dienstag, 25. Dez 2007, 23:01:54 +0900 schrieb James Tucker: > > > This was mercilessly stolen and adapted from a post on Errs blog (only > > google has the answer ;): > > > >       [...] > >   old\_args = ARGV > >   ARGV.size.times { ARGV.shift } > >       [...] > >   old\_args.each { |a| ARGV \<\< a } > >       [...] > > The code is not actually mature. The clearing could be done by an > ARGV.clear; this part won't work either because old\_args will be > cleared as well. > > Besides that the solution works perfectly. Thank you very much! > > Bertram > > -- > Bertram Scharpf > Stuttgart, Deutschland/Germany > [http://www.bertram-scharpf.de](http://www.bertram-scharpf.de)