#!/bin/bash

URL=$(curl -s -D - -o /dev/null http://neverssl.com 2>/dev/null \
    | grep -i '^location:' \
    | head -n1 \
    | sed 's/^[Ll]ocation:[[:space:]]*//' \
    | tr -d '\r')

if [[ -z "$URL" ]]; then
    echo "Already authenticated or no captive portal detected."
    exit 0
fi

echo "Opening captive portal: $URL"
"$BROWSER" "$URL"