My two friends and I have been hosting a dinner series for our friends and friends of friends called “Dine For Friends” at various restaurants across the Bay Area for over a year. Two weekends ago, for our ninth dinner, we had a mishap with the communication; our dinners normally start at 7pm, but the restaurant only had availability at 8pm, but we had published 7pm as the start time and the problem didn’t get caught and confirmed until about 6:30pm. One of the co-hosts suggested that we mass notified people by texting the phone numbers they submitted with their registration at eventbrite.com (we use Eventbrite to organize the sign-ups).

We were hoping to catch people before they headed out or at least inform them that it would be a good hour before we were seated. Unfortunately, since some of the attendees were friends of friends, some of whom we hadn’t met, entering each new number on a phone would be tedious and would potentially cost $0.50 each to send ($0.25 to send and $0.25 to receive without a text package).

So to reduce the effort and the potential costs, I sent text messages using email. Since we didn’t know each person’s cell phone carrier and email-to-SMS is based on carrier, I picked what I guessed to be the top four in the Bay Area (there are web sites which will do it, but for privacy reasons I wanted to go through the carriers themselves to avoid giving up other people’s phone numbers to some random website):

• AT&T
• Verizon
• T-Mobile
• Sprint

Using the carrier’s email for texts and a text file of phone numbers (I had manually stripped out the non digit characters like parentheses and dashes), I ran the following commands in the Terminal app within Mac OS X:

$ sort phonenumdigits.txt | uniq > phonenumdigits-sorted.txt #removes duplicates
$ for i in `cat phonenumdigits-sorted.txt`; do echo $i@txt.att.net,; echo $i@vtext.com,; echo $i@tmomail.net,; echo $i@messaging.sprintpcs.com,; done

And pasted the output in the BCC field and also added their email addresses in case they get email on their phone, too.

I had to think quickly and if I had to do it over again in a more efficient way, I would instead have a phonenums.txt file with phone numbers (okay to have non-digit characters) and a cellprov.txt file with domain names of the carrier email domains and instead run:

$ for i in `sort phonenums.txt | uniq | tr -dc “[:digit:]\n” `; do for j in `cat cellprov.txt`; do echo $i@$j,; done; done

When I was younger, I used to watch the show Ghostwriter where the kids would use their Ghost pens they carried around their necks to send out a message to the others for a team meeting and thought it was a great concept to get in touch with people at the same time (instead of calling each person individually sometimes using the phone tree method). Who needs those Ghostwriter pens when you have cell phones? Though there are some people who do carry their cell phones around their neck.