A script that monitors vaccine appointment availability at New York State-run providers.

vaccine-check.sh

#!/bin/bash

# see also: https://kvz.io/bash-best-practices.html
set -o errexit
set -o pipefail
set -o nounset

# A script to monitor updates to this web page:
# https://am-i-eligible.covid19vaccine.health.ny.gov/
#
# Usage:
# vaccine-check.sh [location 1] [location 2]
#
# Example:
# vaccine-check.sh Javits Queens Brooklyn
#
# The ethics of using this script are complicated, but here is my position: you can help marginally improve
# the equitable distribution of the COVID vaccine in New York State by working with elders and marginalized
# communities who may not be able to easily monitor the website, or run a script like this. In a perfect world
# there would have been better communication/outreach, and a scheduling system that is easier to use. We are
# not in that world yet, so maybe let's look out for each other as best as we can.
#
# You may also want to consider printing out this flyer and distributing: https://tinyurl.com/nysvaccine
#
# 1. Install curl, jq, and setup mailutils and ssmtp
#    See: https://rianjs.net/2013/08/send-email-from-linux-server-using-gmail-and-ubuntu-two-factor-authentication
# 2. Make sure the script can write to a './results' dir
# 3. Try running it: vaccine-check.sh Javits
# 4. Uncomment and edit the variables email_to_list and email_from to send email
# 5. Add this script to a cronjob:
#    * * * * * /path/to/vaccine-check.sh > /dev/null

# Uncomment these vars to send email
# email_to_list="[email 1] [email 2]"
# email_from="[email from]"

if [ $# == 0 ] ; then
	echo "Usage: $0 location"
	echo "       $0 \"SUNY Albany\""
	echo "       $0 Brooklyn Queens Yonkers"
	exit 1
fi

url="https://am-i-eligible.covid19vaccine.health.ny.gov/"
endpoint="https://am-i-eligible.covid19vaccine.health.ny.gov/api/list-providers"
dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"

# Check the endpoint
result=`curl -s "$endpoint"`

for location in "$@" ; do

	# Check whether appointments are available ("AA")
	available=`echo "$result" | jq -r ".providerList[] | select(.providerName | contains(\"$location\")) | .availableAppointments" | head -n 1`

	# Normalize the location name
	provider_name=`echo "$result" | jq -r ".providerList[] | select(.providerName | contains(\"$location\")) | .providerName" | head -n 1 | xargs | sed -e 's/*//g'`

	if [ "$available" == "AA" ] ; then
		message="Vaccine appointments are available at $provider_name $url"
	elif [ "$available" == "NAC" ] ; then
		message="No vaccine appointments are available at $provider_name."
	else
		message="No matches with location name '$location' (check spelling, capitalization)."
	fi

	# Create a results directory
	if [ ! -d "$dir/results" ] ; then
		mkdir "$dir/results"
	fi
	result_file="$dir/results/$provider_name.txt"

	if [[ -z ${email_to_list+x} ]] ; then
		echo "$message"
	else
		if [ ! -f "$result_file" ] || [ $(cat "$result_file") != "$available" ] ; then
			# Only email if the availability changes
			for email_to in $email_to_list ; do
				echo "$message" | mail -a "From:$email_from" \
				                       -s "Vaccine appointments at $location" \
				                       "$email_to"
			done
		fi
	fi

	if [ "$provider_name" != "" ] ; then
		echo "$available" > "$result_file"
	fi
done

I guess depending on what version of mail you're using this script has a bug.

my version:

$ mail --version
mail v14.9.20, 2020-12-12 (built for Linux)

The mail -a flag is used. -a is for attachments. Doesn't make sense to attach "From:$email_form" and it throws an error.

Just get rid of that flag and everything should work assuming you've got a valid .mailrc configured.

Thanks for that @wgwz. The version of mail I'm using, "mail (GNU Mailutils) 3.4," uses -a for "append header." It's a shame the different versions don't standardize this type of thing.