[racket] Embedding multiline shell scipts

Hi all,

I slightly modified the Manfred's code to capture the output (see below). It
seems to do the job, but I haven't tried other cases yet or error handling,
but it's good to continue from here. Thanks Manfred!

Thank you everybody else, as well! I appreciate the shell scripting isn't
the optimal way of doing things. I also treat it as a temporary solution,
and I'll only use it in places I have to. But for now, it allows me to move
on and do things I couldn't otherwise.

br, jukka


(require racket)

(
 (lambda ()
   (define output '())
   (define (print-output in)
     (let loop ((line (read-line in)))
       (if (eof-object? line)
           #t
           (begin (set! output (append output (list line)))
                  ;(printf "~a~n" line)
                  (loop (read-line in))))))

   (define shell-cmd
     (lambda (cmd)
       ;(printf  "~a~n" cmd) ;echoing the cmd which could be omitted
       (let* ([p (process cmd)]
              [stdout (first p)]
              [stdin (second p)]
              [stderr (fourth p)]
              [ctrl (fifth p)])
         (print-output stdout)
         (print-output stderr)
         (close-input-port stdout)
         (close-output-port stdin)
         (close-input-port stderr)
         output)))

   (define test-cmd "
SOMEVAR=\"some-content\"

echo $SOMEVAR
ls
")

   (shell-cmd test-cmd))
 )

>> ("dir1" "dir2" "file1" "file2)

> -----Original Message-----
> From: users-bounces at racket-lang.org
> [mailto:users-bounces at racket-lang.org]On Behalf Of Manfred Lotz
> Sent: 06 February 2011 16:26
> To: users at racket-lang.org
> Subject: Re: [racket] Embedding multiline shell scipts
>
>
> On Sun, 6 Feb 2011 16:06:19 +0200
> "Jukka Tuominen" <jukka.tuominen at finndesign.fi> wrote:
>
> >
> > So, once i have created the script within racket as multiline string,
> > how do I actually run it within racket without writing or reading any
> > external files, and capture the output of the script for further
> > processing (also in racket).
> >
> > In other words, I could write the script into a file and run it with
> > system/output, but how to do it without an external file?
> >
>
> Hmmm, one possibility might be to use process which nicely captures
> output. process is especially good if you have a large amount of output
> as you can process the output (e.g. write it to a log file) line by
> line.
>
>
>
> Example: Here the output of the command(s) will just be echoed to
> stdout and to stderr.
>
> (define (print-output in)
>       (let loop ((line (read-line in)))
>         (if (eof-object? line)
>             #t
>             (begin (printf "~a~n" line)
>                    (loop (read-line in))))))
>
> (define shell-cmd
>       (lambda (cmd)
>         (printf  "~a~n" cmd) ;echoing the cmd which could be omitted
>         (let* ([p (process cmd)]
>                [stdout (first p)]
>                [stdin (second p)]
>                [stderr (fourth p)]
>                [ctrl (fifth p)])
>           (print-output stdout)
>           (print-output stderr)
>           (close-input-port stdout)
>           (close-output-port stdin)
>           (close-input-port stderr))))
>
> (define test-cmd "
> SOMEVAR=\"some-content\"
>
> echo $SOMEVAR
> ")
>
> (shell-cmd test-cmd)
>
>
>
> I don't know how to merge stdout and stderr in proper sequence. People
> who know racket better than me may interfere to improve my example.
>
>
>
> --
> Manfred
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