- I may have gone a little overboard with this one.

Documents/train-wifi.sh

 #!/bin/sh
 set -eu
+# The MIT License (MIT)
+#
+# Copyright (c) 2016 Adar Nimrod <nimrod@shore.co.il>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
 
 # Logs in to the Israeli train's wifi.
+# Requires: cURL, sh, awk, logger.
 # To install run:
-# sudo cp --preserve=mode "$HOME/Documents/train-wifi.sh" "/etc/NetworkManager/dispatcher.d/90trainwifi"
+# sudo cp --preserve=mode train-wifi.sh /etc/NetworkManager/dispatcher.d/90trainwifi
 
+die () {
+    echo $@ | logger
+    exit 1
+}
+
+debug () {
+    [ -n ${DEBUG:+x} ] && echo $@ | logger
+}
+
+if [ $# -ne 2 ]
+then
+    echo "Usage: $0 interface action"
+    exit 1
+else
     interface="$1"
-status="$2"
+    action="$2"
+fi
+
+which curl > /dev/null || die "Can't login to the train wifi, cURL is not installed."
+which awk > /dev/null || die "Can't login to the train wifi, awk is not installed."
+which logger > /dev/null || dir "Can't login to the train wifi, logger is not installed."
 
-if [ "$interface" = "ISRAEL-RAILWAYS" ] && [ "$status" = "up" ]
+if [ "$interface" = "ISRAEL-RAILWAYS" ] && [ "$action" = "up" ]
 then
-    curl http://10.5.4.1/loginHandler.php?allowAccess=true
+    redirect_url="$(curl --output /dev/null --silent --write-out '%{redirect_url}' http://google.com/)"
+    debug "Train wifi redirect url: $redirect_url"
+    login_url="$(echo "$redirect_url" | awk -F\? '{printf("%s?allowAccess=true", $1)}' )"
+    debug "Train wifi login url: $login_url"
+    curl "$login_url"
+else
+    debug "Interface isn't ISRAEL-RAILWAYS or action isn't up, not signing in to the train wifi."
 fi