A helper for simplifying and remembering the add/route default gateway commands

router.sh

#!/bin/bash

CONFIG=~/.route.conf

function usage() {
    echo -e "Usage: `basename $0` <options>\noptions:"
    grep "^function" $0 | sed 's/function/  /g' | sed 's/[{()]//g'
}

function list() {
    route -n
}

function reset () {
    echo "" > $CONFIG
}

function cache () {
    cat $CONFIG
}

config () {
    local op=$1
    local gateway=$2
    local interface=$3
    local metric=$4
    if [ ! -f $CONFIG ]; then
        touch $CONFIG
    fi
    if [ "$gateway" = "" ]; then
        gateway=$(grep gateway -A 1 $CONFIG | tail -1)
        if [ "$gateway" = "" ] || [ "$gateway" = "[gateway]"  ]; then
            read -p "Enter gateway: " gateway
        fi
    fi
    if [ "$interface" = "" ]; then
        interface=$(grep interface -A 1 $CONFIG | tail -1)
        if [ "$interface" = "" ] || [ "$interface" = "[interface]"  ]; then
            read -p "Enter interface: " interface
        fi
    fi
    if [ "$metric" = "" ]; then
        metric=$(grep metric -A 1 $CONFIG | tail -1)
        if [ "$metric" = "" ] || [ "$metric" = "[metric]"  ]; then
            read -p "Enter metric: " metric
        fi
    fi
    echo -e "[gateway]\n$gateway" > $CONFIG
    echo -e "[interface]\n$interface" >> $CONFIG
    echo -e "[metric]\n$metric" >> $CONFIG
    local cmd="sudo route $op -net default gw $gateway netmask 0.0.0.0 dev $interface metric $metric"
    echo -e "$cmd\n"
    $cmd
}

function add() {
    config add $@
    list
}

function del() {
    config del $@
    list
}

if [ -z "$1" ]; then
    usage
else
    $@
fi