# Execute ruby entered in view in controller **URL:** \ **Category:** Rails\ **Created:** [February 21, 2009, 1:37pm UTC](https://www.ruby-forum.com/t/execute-ruby-entered-in-view-in-controller/160961 "2009-02-21T13:37:23Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![sudhi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dbc845/32.png) [@sudhi](https://www.ruby-forum.com/u/sudhi)\ **Post date:** [February 21, 2009, 1:37pm UTC](https://www.ruby-forum.com/t/execute-ruby-entered-in-view-in-controller/160961/1 "2009-02-21T13:37:23Z")
HI, I have a requirement where a user could enter ruby scripts in the view( typically a text area) and the controller should pick this text on submit and execute the script(content of text area) line by line. How should I do it in rails? Thanks, Sudhi ---
**Author:** ![sudhi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dbc845/32.png) [@sudhi](https://www.ruby-forum.com/u/sudhi)\ **Post date:** [February 21, 2009, 2:16pm UTC](https://www.ruby-forum.com/t/execute-ruby-entered-in-view-in-controller/160961/2 "2009-02-21T14:16:56Z")
On 21 Feb 2009, at 12:37, Sudhi K. wrote: > HI, > I have a requirement where a user could enter ruby scripts in the > view( > typically a text area) and the controller should pick this text on > submit and execute the script(content of text area) line by line. > > How should I do it in rails? Well you could just use eval, but that sounds like an incredibly bad idea security wise. Fred ---
**Author:** ![sudhi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dbc845/32.png) [@sudhi](https://www.ruby-forum.com/u/sudhi)\ **Post date:** [February 21, 2009, 2:31pm UTC](https://www.ruby-forum.com/t/execute-ruby-entered-in-view-in-controller/160961/3 "2009-02-21T14:31:08Z")
Frederick C. wrote: > On 21 Feb 2009, at 12:37, Sudhi K. wrote: > > > HI, > > I have a requirement where a user could enter ruby scripts in the > > view( > > typically a text area) and the controller should pick this text on > > submit and execute the script(content of text area) line by line. > > > > How should I do it in rails? > > Well you could just use eval, but that sounds like an incredibly bad > idea security wise. > > Fred I did try ‘eval @test.script’ where the script was filled in the @test.script but that does not work. Is there a safe way of handling execution errors that can occur when executing scripts ---
**Author:** ![sudhi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dbc845/32.png) [@sudhi](https://www.ruby-forum.com/u/sudhi)\ **Post date:** [February 22, 2009, 12:43am UTC](https://www.ruby-forum.com/t/execute-ruby-entered-in-view-in-controller/160961/4 "2009-02-22T00:43:09Z")
On Feb 21, 6:51 pm, Matt J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > +1 to Fred’s comment about security - there are some solutions that > can mitigate > the security problems, but eval’ing code sent from the web is a BAD > IDEA. If you > have _any_ user access control in your system, this can get around it. > > There are a couple things you might be interested in: One thing I’ve been thinking recently is that jruby might be neat for this, assuming you can just lean on Java’s security stuff (no idea if you can). Fred ---
**Author:** ![sudhi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dbc845/32.png) [@sudhi](https://www.ruby-forum.com/u/sudhi)\ **Post date:** [February 22, 2009, 8:32am UTC](https://www.ruby-forum.com/t/execute-ruby-entered-in-view-in-controller/160961/5 "2009-02-22T08:32:58Z")
Frederick C. wrote: > On Feb 21, 6:51�pm, Matt J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > +1 to Fred’s comment about security - there are some solutions that > > can mitigate > > the security problems, but eval’ing code sent from the web is a BAD > > IDEA. If you > > have _any_ user access control in your system, this can get around it. > > > > There are a couple things you might be interested in: > > One thing I’ve been thinking recently is that jruby might be neat for > this, assuming you can just lean on Java’s security stuff (no idea if > you can). > > Fred Thanks for the inputs. Yes, there could be some security implications with this but is there a neat way of say providing a tool which povides the user a way to control script execution on the server? Also the flexibility of ordering scripts is important, that is why a full fledged ruby editor is required on the browser. Is there any view plugin which can accept ruby scripts? ---
**Author:** ![sudhi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/dbc845/32.png) [@sudhi](https://www.ruby-forum.com/u/sudhi)\ **Post date:** [February 21, 2009, 7:52pm UTC](https://www.ruby-forum.com/t/execute-ruby-entered-in-view-in-controller/160961/6 "2009-02-21T19:52:04Z")
On Feb 21, 8:31 am, Sudhi K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > Well you could just use eval, but that sounds like an incredibly bad > > idea security wise. > > > Fred > > ## I did try ‘eval @test.script’ where the script was filled in the @test.script but that does not work. Is there a safe way of handling execution errors that can occur when executing scripts +1 to Fred’s comment about security - there are some solutions that can mitigate the security problems, but eval’ing code sent from the web is a BAD IDEA. If you have _any_ user access control in your system, this can get around it. There are a couple things you might be interested in: - \_why’s Sandbox class. It’s mostly a proof of concept, but it might have some ideas. Note that while it can keep some bad things from happening, you’ll still need to give the sandboxed code access to the DB (that is why you’re evaling Ruby from the web, right?) - at the very least, some kind of usage of $SAFE, which could protect your environment a little. But then you’ve got threading problems… - if you just want a console-like environment, Kawaii (http:// [GitHub - eviltrout/kawaii: Kawaii is like a web frontend to script/console for your Rails apps, with nicely formatted output](http://github.com/eviltrout/kawaii)) might save you from re-inventing the wheel. Finally, to answer your actual question, you’d use a rescue clause to catch execution errors. Check your favorite Ruby reference for more details. –Matt J.