[Haskell-cafe] Standard output of exec

[Ernesto Rodriguez]

Hi Michael,

Thank you for your answer. Conduits certainly are the best approach, but
the output I am going to read is very short and the external program will
only be called once or twice per execution so I think Lazy IO won't be
problematic here.

Best regards,

Ernesto

On Thu, Dec 11, 2014 at 10:18 AM, Michael Snoyman <michael at snoyman.com>
wrote:

> You can use readProcess[1], but it has some downsides:
>
> 1. Can't specify all options to CreateProcess, e.g., working directory and
> environment variables.
> 2. Relies on lazy I/O
>
> I use Data.Conduit.Process[2] for this kind of thing, which has a full
> tutorial[3]. However, it *does* involve non-base dependencies.
>
> [1]
> http://www.stackage.org/haddock/2014-12-10-ghc78-exc/process-1.2.0.0/System-Process.html#v:readProcess
> [2]
> http://www.stackage.org/haddock/2014-12-10-ghc78-exc/conduit-extra-1.1.4.2/Data-Conduit-Process.html
> [3]
> https://www.fpcomplete.com/user/snoyberg/library-documentation/data-conduit-process?show=tutorials
>
> On Thu Dec 11 2014 at 11:11:12 AM Ernesto Rodriguez <neto at netowork.me>
> wrote:
>
>> Dear All,
>>
>> I have a program which invokes an external program via exec. I wish to
>> capture the standard output of the program without using external
>> (temporary) files. Is it possible to create an in memory handle which I can
>> tell exec to use as standard output of the invoked program. It would be
>> great if it can be done without any extra dependencies.
>>
>> Best,
>>
>> --
>> Ernesto Rodriguez
>>
>> Masters Student
>> Computer Science
>> Utrecht University
>>
>> www.netowork.me
>> github.com/netogallo
>>
>>
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>> Haskell-Cafe mailing list
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>>
>


-- 
Ernesto Rodriguez

Masters Student
Computer Science
Utrecht University

www.netowork.me
github.com/netogallo
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