Creating script to take picture and email it

Question

I recently read an article about someone who created an automator script that would take a picture using a MacBook iSight camera and email it each time the MacBook awoke from sleep. Several laptops have been stolen from my workplace and I thought this would be a great way of figuring out the thief were my laptop ever stolen.
When I looked at the script, I noticed that it opens up PhotoBooth and Mail so that the user in front of the computer would see that their picture was being taken and that an email message was sent.
In the name of stealthness, I was hoping to duplicate this process in a unix script. I have a few pieces figured out, but I need some guidance on other issues.
What I know:
1. How to use sleepwatcher to call a unix script upon the MacBook waking.
2. How to take a stealth image using the commandline command "camcapture".
What I would like to know
1. What unix command could I use to check to see if the MacBook has a viable internet connection?
2. If there is a viable connection, send an email with the image taken to a particular email address and with a particular subjectline.
3. If there is not a viable internet connection, save the email and check for a viable internet connection each 5 minutes (or so) and send the email as soon as an internet connection is achieved.
Thank you in advance for any guidance you can offer.

Answer 1

Hi Mahongue,
   I'm sorry for being absent for a while but in your case that seems to have been a good idea. I think you deserve the star more than I because you seemed to have worked it all out. Of course I couldn't tell you what server your e-mail account uses but it doesn't matter that much in the ping statement. If you can ping mail.yahoo.com, I'm sure that would indicate that you have an internet connection that would allow you to send mail to a yahoo account. I see your point about e-mail being the best solution in case you don't have a reliable server of your own. Of course you can get around the dynamic IP address the way I do, with DynDNS.org. They allow you to change your DNS listing programmatically and you do that at boot. Of course that wouldn't allow you to reliably scp to that machine unless it's always up.
   Your idea of testing the return value of ping command will work in principle. I tested it and ping returns an error if either the lookup fails or the ping times out. I've never used the syntax you did in the if clause. What shell are you using? In a Bourne-type shell, you shouldn't need the parentheses. You could use something like:
if ping -c 1 mail.yahoo.com >/dev/null 2>&1; then
   <Invoke Network Usage>
fi
The redirection avoids cluttering the output of your script with the ping output.
If you're interested, the CheckForNetwork function in the /etc/rc.common script is:
# Determine if the network is up by looking for any non-loopback
# internet network interfaces.
CheckForNetwork()
   local test
   if [ -z "${NETWORKUP:=}" ]; then
   test=$(ifconfig -a inet 2>/dev/null | sed -n -e '/127.0.0.1/d' -e '/0.0.0.0/d' -e '/inet/p' | wc -l)
   if [ "${test}" -gt 0 ]; then
      NETWORKUP="-YES-"
   else
      NETWORKUP="-NO-"
   fi
   fi
and usage is:
CheckForNetwork
if [ "${NETWORKUP}" = "-YES-" ]; then
   <Invoke Network Usage>
fi
If you copy-and-paste any of this code, be sure to replace the non-breaking spaces used for indention with real spaces.
   Thanks for the link to the mail_files script!! That is really impressive! Naturally I saved it. The link you posted is broken at the moment but it's probably one of those sites that throttle traffic by shutting it down for a while when it's "overused". Maybe you've made him popular. Anyway, I got a version of the same script elsewhere but mine says that the uuencoding is untested. Yours doesn't say that, does it? Have you tested that with your version?
   Dave's script still uses Perl to do base64 encoding. It should still be possible to do this in Perl and there are advantages to letting library code handle certain tasks. That way, if a protocol changes someone will likely upgrade the library for you. I think that on another thread you asked about how to add an attachment in the code that we were discussing on that other thread. However, I thought you said that you had Perl code to do that. I was just suggesting that you put the two together.
Gary
~~~~
   The party adjourned to a hot tub, yes.
   Fully clothed, I might add.
         -- IBM employee, testifying in California State Supreme Court