Things I'll Forget In A Month Tech scratchpad and musings

Remote controlling an iSight

One of the neat things to do with a remote Mac is to control the built-in iSight remotely to snap photos. There are several commercial applications to do this, but we're going for the low-tech approach: taking pictures via command line over SSH. The free app iSightCapture is designed to do this, but hasn't been updated in awhile and doesn't work as-is on anything after 10.4.9 (including 10.5 and 10.6) due to new security restrictions. I put together a little script that basically wraps iSightCapture so that it works as designed on an up-to-date system.

You'll need to have iSightCapture installed and in your $PATH -- you can either do that by manually installing the binary at the above link or via MacPorts with 'sudo port install isightcapture'. Then create a new file in /usr/local/bin (or wherever) and put in the following Perl snippet:

#!/usr/bin/perl -w

use strict;

foreach (split(/\n/, `ps aux | grep loginwindow`)) {
  if (/^\w+\s+(\d+).+?loginwindow\.app/) {
    my $sudo = ($> == 0) ? '' : 'sudo ';
    exec("$sudo launchctl bsexec $1 isightcapture @ARGV");
    exit;
  }
}

print "Failed to find loginwindow process.\n";

I called the new binary 'snap', so at the command-line, I just type 'snap image.jpg' instead of 'isightcapture image.jpg'. The only real difference from isightcapture is that you need sudo -- that's an intentional Mac OS X security restriction that can't be circumvented (and probably shouldn't) as far as I know. All the iSightCapture command-line options should work as-is, so just refer to its documentation for those. The wrapper script is definitely a hack that might break with a future OS update, but has worked flawlessly for me on several different machines running a variety of Mac OS X versions.