easy question: getting shell output?

easy question: getting shell output?

[Ciaran O'Riordan]

Hi all!

(I think this is my first post to the list)

I'm having a small problem capturing the output of
a shell command.

I want the output of 'ls -1' to be stored in a
variable which I will later split into a list.

I've tried the obvious things like changing the
default output port to a newly created string port
but no matter what I try the output always gets
displayed to my terminal.

This must be a common situation, I've read the
guile reference and the guile tutorial but can't
find an answer.

any pointers would be appreciated.


Ciaran O'Riordan


_________________________________________________________________
MSN Photos is the easiest way to share and print your photos: 
http://photos.msn.com/support/worldwide.aspx


_______________________________________________
Guile-user mailing list
Guile-user@gnu.org
http://mail.gnu.org/mailman/listinfo/guile-user

Re: easy question: getting shell output?

[Christopher Cramer]

On Fri, Apr 26, 2002 at 04:02:26PM +0000, Ciaran O'Riordan wrote:
> I'm having a small problem capturing the output of
> a shell command.
> 
> I want the output of 'ls -1' to be stored in a
> variable which I will later split into a list.
> 
> I've tried the obvious things like changing the
> default output port to a newly created string port
> but no matter what I try the output always gets
> displayed to my terminal.

The default output port is only used by Guile. A separate process
(such as ls) isn't going to use it.

What you probably want is open-input-pipe, e.g.:

(use-modules
    (ice-9 rw)
    (ice-9 popen))

(let (
	(input (open-input-pipe "ls -1"))
	(buffer (make-string 256)))
    (let loop ((l '()))
        (let ((n (read-string!/partial buffer input)))
            (if n
                (loop (cons (substring buffer 0 n) l))
                (apply string-append (reverse! l))))))

-- 
Christopher Cramer <crayc@pyro.net> <http://www.pyro.net/~crayc/>
On résiste à l'invasion des armées; on ne résiste pas à l'invasion
des idées.  -- Victor Hugo

_______________________________________________
Guile-user mailing list
Guile-user@gnu.org
http://mail.gnu.org/mailman/listinfo/guile-user

Re: easy question: getting shell output?

[Thien-Thi Nguyen]

   From: "Ciaran O'Riordan" <ciaran_o_riordan@hotmail.com>
   Date: Fri, 26 Apr 2002 16:02:26 +0000

   any pointers would be appreciated.

you can use (ice-9 popen) facilities directly, or higher abstractions.
for examples of the latter, see (ttn make-buffered-caller) and friends:

 http://www.glug.org/people/ttn/software/ttn-pers-scheme/dist/0.29/ttn/

make-buffered-caller is used in lots of places:

 http://www.glug.org/maint/cron-job-map.html

probably i'll contribute make-buffered-caller to guile at some point.

thi

_______________________________________________
Guile-user mailing list
Guile-user@gnu.org
http://mail.gnu.org/mailman/listinfo/guile-user