Shell Executing 'aplay' from Node.js on Raspbian

[Scott Elcomb]

Hi all; the following is a message I recently sent to the node.js
list.  Unfortunately there hasn't been any feedback as yet and I need
to figure out where the issue is soon.  It's my hope that someone here
may have run into something similar or an inkling of where the trouble
is.

A smaller version of the example (still in node.js but without the
express framework) works just fine.  I can post the code if desired.

I suspect it's an issue with the environment (as seen by express) but
I'm not terribly familiar with ALSA; it may be something else
entirely.

Might be a long shot but any pointers or suggestions would be most appreciated.

TIA,
-Scott

[-- Message Begins --]

I'm trying to work around the lack of web audio on a Raspberry Pi +
Chromium project and have run into a bit of trouble: I need to play a
short sound when express responds to a route.  The app is currently
running on node v0.6.19 & express 3.0.6.

If I run the aplay command (below) from bash, the sound card is
detected and the file is played.  When run from the express route
handler, the sound card is not detected and no sound is played.  (It's
the same user in both cases.)

I'm not sure where the issue is - any pointers would be most appreciated.

[-- example server.js starts --]
var server = require('express')()
  , exec = require('child_process').exec
  , util = require('util')
;

function puts(error, stdout, stderr) {
    util.puts(stdout);
    util.puts(stderr);
}

server.get('/sound', function(req, res) {
    // env not sanitized for debugging purposes
    exec("/usr/bin/aplay /tmp/testsound.wav"
        , { cwd: process.env.pwd, env: process.env }
        , function(error, stdout, stderr) {
            puts(error, stdout, stderr);
            res.send('ok');
        });
});

server.listen(5151);
[-- example server.js ends --]

-- 
  Scott Elcomb
  @psema4 on Twitter / Identi.ca / Github & more

  Atomic OS: Self Contained Microsystems
  http://code.google.com/p/atomos/

  Member of the Pirate Party of Canada
  http://www.pirateparty.ca/
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