#!/usr/bin/env sh
#
# Check for internet connectivity.
# Returns 0 if connectivity exists, 1 if it does not.

hasconnec=0
for intf in /sys/class/net/*; do
    case $intf in
    "/sys/class/net/lo") break ;;
    *)
        [ "$(cat "$intf/carrier")" = 1 ] && hasconnec=1
        ;;
    esac
done

if [ $hasconnec -ne 1 ]; then
    ping -q -w 1 -c 1 8.8.8.8 >/dev/null 2>&1 && hasconnec=1
fi

if [ $hasconnec -eq 1 ]; then
    exit 0
else
    exit 1
fi