Find the IP of the local machine and make a url to localhost server

makeUrl.sh

#!/bin/sh

IP=""

# find all the active connections of the machine, 
# and find the IP address of the first one
for i in $(ifconfig -lu) ; do
    if (ifconfig $i | grep -q "status: active") ; then
        IP=$(ifconfig $i | grep -i "inet ")
        break
    fi ;
done

# Finish process if no active connection:
if [ "$IP" = "" ] ; then 
    echo "no active connection"
else 
    # trim the IP address to use only the first part:
    INET=$(awk '{split($0, array); print array[2]}' <<< $IP)
    # parse it to the url:
    URL="http://$INET:3000"
    # if other port is passed as an argument, parse it instead of the 
    # default one:
    if [ "$1" != "" ] ; then
        URL="http://$INET:$1"
    fi
    echo $URL
fi