Thanks Andreas, I was just coming to the conclusion you have pointed out. I
haven't had a computer to try it - but I'll try your example.
If it works, I think this should almost be in the std image so that Pharo plays
better with others straight out of the box.
The " issue is when calling from other other languages (e.g. Nodejs). Try
passing some Json as a parameter using exec and you hit this issue with the
eval handler - but maybe with my own handler I can do something better? I need
to study this and will report back.
Thanks,
Tim
Sent from my iPhone
> On 1 Jul 2017, at 17:17, Andreas Sunardi <a.suna...@gmail.com> wrote:
>
> If I'm not mistaken, this is Pharo's eval command line handler you're talking
> about. If so, it is not correct to say 'it also return the result of that
> method or yourself'. To return the result (and print it to stdout) of that
> method is the goal of eval command line handler.
>
> How about making your method to return empty string, or better create your
> own command line handler. I believe the minimal you need to do is to subclass
> EvaluateCommandLineHandler, override class method #commandName and override
> method #evaluate:. Something like this, perhaps
>
> ProceesCommandLineHandler class >> commandName
> ^ 'process'
>
> ProcessCommandLineHandler >> evaluate: aStream
> Smalltalk evaluate: aStream.
>
> Save your image, then you can call
> ./pharo -headless myimage.image process StandardFileStream stdout print: 42
>
> and it'll print 42 and nothing else.
>
> I'm not sure I understand the double quote (") character issue that \"
> solves. Example?
>
>
>
>> On Thu, Jun 29, 2017 at 7:02 AM, Tim Mackinnon <tim@testit.works> wrote:
>> Hi - I've been playing with using Pharo with Aws lambda and have got an
>> image to launch in that environment.
>>
>> However now I need to better integrate Pharo with its calling environment -
>> and I know there was a concerted effort to make Pharo play better which I
>> should be able to leverage.
>>
>> So I am calling Pharo from a NodeJS wrapper (the suggested aws method for
>> integrating alternative languages like Ruby, Go etc).
>>
>> I got this to work - however as an observation, it is rather awkward passing
>> parameters to Pharo using the "eval" mechanism as other languages and
>> environments frequently use the " character (particularly with Json) and
>> this causes Pharo to fail if you don't \" this. I'm wondering if others have
>> noted this and whether we can do this better somehow? For now a little
>> nodeJS regex fu gets me past it.
>>
>> However my next question is about passing information back to the calling
>> application.
>>
>> I can see that there is a stdout method on Fikestream that I can write to
>> (great), however in my ./pharo eval call, which sends to a class method
>> doing this - it also returns the result of that method or yourself? I guess
>> this convention is great for the "eval 42 factorial" example but not so
>> great of you just want to return some Json via stdout in a format of the
>> calling environment?
>>
>> Is there something simple trick I can do to stop this extra result and just
>> let me use stdout myself? Or do I have to return a Smalltalk string and then
>> regex convert it to a new format in my calling language?
>>
>> I'm wondering if others have done this, or if anyone has some advice?
>>
>> It feels like a usecase that we might be able to do better somehow?
>>
>> Tim
>>
>> Sent from my iPhone
>>
>
