[sh] get auth token for IVLE LAPI

auth-token.sh

#!/bin/sh

# user-specific info

API_KEY=
USER_ID=""  # be careful about escaping!
PASSWORD="" # ditto

# add additional curl options here - eg. -v
CURL='curl'

# config
COOKIE_JAR=./ivle.cookies
LOGIN_URL="https://ivle.nus.edu.sg/api/login/?apikey=$API_KEY"

echo "getting cookie..."
viewstate=$(
	$CURL "$LOGIN_URL" | \
	awk '/name="__VIEWSTATE"/ { split($5,parts,"\""); print parts[2] }'
)

echo "logging in..."
token=$($CURL "$LOGIN_URL" \
	-L \
	-b "$COOKIE_JAR" -c "$COOKIE_JAR" \
	--data-urlencode "__VIEWSTATE=$viewstate" \
	--data-urlencode "userid=$USER_ID" \
	--data-urlencode "password=$PASSWORD") \
	|| printf >2 "failed to get token:\n%s" "$token" \
	&& printf "your token is:\n%s\n" "$token"