updates /etc/hosts whenever a host ip changes useful for creating host aliases usage: update-hosts <host_alias> <host_ip>

gistfile1.sh

hosts=/etc/hosts
host=$1
ip=$2

if [ "$ip" = "" ]; then
    ip=$(wget -qO- http://checkip.dyndns.org | cut -f2 -d":" | cut -f1 -d"<" | sed "s/ //")
fi

line=$(grep $host $hosts)

if [ $? -ne 0 ]; then
    echo "$ip\t$host\t# $(date)" >> $hosts
    exit 0
fi

oldip=$(echo "$line" | awk '{print $1}')

if [ "$ip" != "$oldip" ]; then
    sed -i "s/$line/$ip\t$host\t# $(date)/" $hosts
fi