Checks for authorized Wi-Fi SSID or connected Ethernet before performing backup.

check_network_before_backup.sh

#!/bin/bash
# Checks for authorized Wi-Fi SSID or connected Ethernet before performing
# backup.

RUN=false;
AUTHFILE=~/.config/authorized_netwoks.txt;
WIFI=$(iwgetid --raw);
ETH_IF=eth0;
ETH=$(ip link show $ETH_IF | perl -n -e'/state (\w+)/ && print $1');

if [ "$ETH" = "UP" ]; then
    echo "Performing backup over Ethernet";
    RUN=true;
elif [ -f $AUTHFILE ]; then
    if [ ! -z "^$WIFI$" ]; then
        if [ ! -z $(grep "$WIFI" "$AUTHFILE") ]; then
            echo "Performing backup over Wi-fi: $WIFI";
            RUN=true;
        else
            echo "Prohibited backup due to unauthorized Wi-fi: $WIFI";
        fi
    else
        echo "Not connected to a network."
        exit 1;
    fi
else
    echo "No AUTHFILE found!";
    exit 1;
fi

if $RUN; then
    echo "Starting backup..."
    # Do stuff here
fi

exit 0;