#!/bin/bash

# Validate that we get 1 and only 1 parameter
case $# in
  1) ;;
  *) /usr/bin/echo Usage: $0 ip-address-or-dns-name
     exit 1 ;;
esac
# the $1 parameter is the IP address assigned to our system

# Establish today's date (for html)
DATE=`/usr/bin/date`

# allocate empty tempfile, terminate if unable to allocate
TEMPFILE=`/usr/bin/mktemp /tmp/$1=XXXXXX` || exit 2

# build webpage (redirect) html into tempfile
# NB: $1 is our local IP address, passed in from ip-up
#     $DATE is the current date and time
#     With the "here document", these variables will
#     be substituted into the stream by the shell
/usr/bin/cat >$TEMPFILE <<END
<html>
<head>
<!-- $DATE -->
<meta http-equiv="refresh" content="0;url=http://$1/">;
</head>
</html>
END

# send webpage (redirect html) to webserver
#  ISP_ADDRESS is FTP address of ISP's web server
#  ISP_USERID  is my userid at ISP's FTP server
#  ISP_PASSWD  is my password at ISP's FTP server
#  NB: ISP_USERID, ISP_PASSWD set as local environment
#      vars so that they don't appear as parameters
#      in local 'ps ax' listings
#      With the "here document", these variables will
#      be substituted into the stream by the shell
ISP_ADDRESS=webserver.isp.com
ISP_USERID=username
ISP_PASSWD=password

/bin/ftp -n <<STOP
open $ISP_ADDRESS
user $ISP_USERID $ISP_PASSWD
ascii
put $TEMPFILE index.htm
bye
STOP

# delete tempfile
/bin/rm -f $TEMPFILE

# terminate
exit 0