#!/usr/bin/ksh93
################################################################
#### Copyright 2007 By Dana French, All Rights Reserved
#################################################################
function usagemsg_email2hex {
  print -- "
Program: email2hex

Generate a javascript and HEX code representation of an
HTML Anchor HREF tag containing a \"mailto:\" email
address.  The generated javascript can then be imbedded
within an HTML document and the email addresses can only 
be viewed when processed by a browser.  This makes it much
more difficult to scrape email addresses from the source
code of an HTML document.

Usage: ${1##*/} [-?vV] -e 'emailAddress' -t 'Link Text String'
                 [-p 'Prepended Text'] [-s 'Suffix Text']

  Where:
    -e emailAddress = Email address to encode as HEX
    -t linkText     = HTML Link text string to encode as HEX
    -p PrependText  = Text string to prepend before the Anchor HREF Tag
    -s SuffixText   = Text string to attach to the end of the Anchor HREF Tag
    -v              = Verbose mode - displays email2hex function info
    -V              = Very Verbose Mode - debug output displayed

Author: Dana French (dfrench@mtxia.com)

Copyright 2007 By Dana French, All Rights Reserved

\"AutoContent\" enabled
"
}
################################################################
#### 
#### Description:
#### 
#### Generate a javascript and HEX code representation of an
#### HTML Anchor HREF tag containing a \"mailto:\" email
#### address.  The generated javascript can then be imbedded
#### within an HTML document and the email addresses cannot
#### be viewed or easily scraped from the pages.
#### 
#### Assumptions:
#### 
#### This script will probably not work with IBM's version of
#### ksh93 since IBM's ksh93 is about 7 years out of date.  You 
#### will need to download a recent version of ksh93 from
#### www.kornshell.com to run this script with IBM AIX.
#### 
#### Dependencies:
#### 
####     None
#### 
#### Products:
#### 
#### This script generates a snippit of HTML code as a SCRIPT
#### tag. The SCRIPT tag contains HEX code representations of
#### the email address and descriptions provided on the
#### command line of this shell script.
#### 
#### Configured Usage:
#### 
#### This script can be run as a function or from the command
#### line. A typical command line would appear as:
#### 
#### email2hex -e "info@mtxia.com" -t "Mt Xia Information" -p "For Info: "
#### 
#### Details:
#### 
################################################################
function mkascii
{
 typeset VAL='${CNT}'
 [[ "_${2}" != "_" && "_${2}" =  "_8" ]] && VAL='$( printf "%o" 0x${i}${j} )'
 [[ "_${2}" != "_" && "_${2}" = "_16" ]] && VAL='${i}${j}'
 nameref ASCII_TABLE=$1
 typeset CNT=0
 for i in 0 1 2 3 4 5 6 7 8 9 A B C D E F
 do
  for j in 0 1 2 3 4 5 6 7 8 9 A B C D E F
  do
   eval ASCII_TABLE[\\$(print -- $( printf "\\\0%o" 0x${i}${j} ) )]=\"${VAL}\" 2>/dev/null
   (( CNT = CNT + 1 ))
  done
 done
}
################################################################
function email2hex {
  typeset VERSION="1.0"
  typeset TRUE="1"
  typeset FALSE="0"
  typeset EXITCODE="0"
  typeset VERBOSE="${FALSE}"
  typeset VERYVERB="${FALSE}"
  typeset EMAIL=""
  typeset LINKTEXT=""
  typeset PREPTEXT=""
  typeset SUFFTEXT=""
  typeset MSG="<a href=\"mailto:${EMAIL}\">${LINKTEXT}</A>"
  typeset SCRIPT_TAGBEG="<SCRIPT Language='javascript' Type='text/javascript'>document.writeln(unescape(''+\n'"
  typeset SCRIPT_TAGEND="</SCRIPT>"
  typeset DENOM="16"
  typeset -A HEX
  typeset IDX

#### 
#### Process the command line options and arguments, saving
#### the values as appropriate.
#### 

  while getopts ":vVe:t:p:s:" OPTION
  do
      case "${OPTION}" in
          'e') EMAIL="${OPTARG}";;
          't') LINKTEXT="${OPTARG}";;
          'p') PREPTEXT="${OPTARG}";;
          's') SUFFTEXT="${OPTARG}";;
          'v') VERBOSE="${TRUE}";;
          'V') VERYVERB="${TRUE}";;
        [?:#]) usagemsg_email2hex "${0}" && return 1 ;;
      esac
  done
   
  shift $(( ${OPTIND} - 1 ))
  
  trap "usagemsg_email2hex ${0}" EXIT
  if [[ "_${EMAIL}" == "_" ]]
  then
      print -u 2 "# ERROR: Email address not specified"
      return 2
  fi
  if [[ "_${LINKTEXT}" == "_" ]]
  then
      print -u 2 "# ERROR: Link text not specified"
      return 3
  fi
  trap "-" EXIT
  
#### 
#### Display some program info and the command line arguments specified
#### if "VERBOSE" mode was specified.
#### 

  (( VERYVERB == TRUE )) && set -x
  (( VERBOSE  == TRUE )) && print -u 2 "# Version........: ${VERSION}"
  (( VERBOSE  == TRUE )) && print -u 2 "# Email Address..: ${EMAIL}"
  (( VERBOSE  == TRUE )) && print -u 2 "# Link Text......: ${LINKTEXT}"
  (( VERBOSE  == TRUE )) && print -u 2 "# Prepended Text.: ${PREPTEXT}"
  (( VERBOSE  == TRUE )) && print -u 2 "# Suffix Text....: ${SUFFTEXT}"

################################################################

  MSG="${PREPTEXT}<a href=\"mailto:${EMAIL}\">${LINKTEXT}</A>${SUFFTEXT}"
  mkascii HEX 16

  (( VERBOSE  == TRUE )) && print -u 2 "# HREF Anchor Tag: ${MSG}"

  for (( i=0; i<${#MSG}; ++i ))
  do
    PARS[i]="${MSG:i:1}"
  done  

#### The substitution operator with pattern replacement does not
#### seem to work under the cygwin implementation of ksh93.  The
#### above "for" loop was added to replace the following code.

#   IFS=$'|'
#   PARS=( ${MSG//(?)/|\1} )
#   unset PARS[0]
#   IFS=$' \t\n'

  (( VERBOSE  == TRUE )) && print -u 2 "# Parsed Array...: ${PARS[@]}"
  print -n -- "${SCRIPT_TAGBEG}"

  for IDX in "${!PARS[@]}"
  do
    (( VERBOSE  == TRUE )) && print -u 2 "# Char: ${PARS[IDX]}     HEX: ${HEX[${PARS[${IDX}]}]}"
    print -n -r -- "%${HEX[${PARS[${IDX}]}]}"
    (( ( IDX % DENOM ) == 0 )) && print -n -- "'+\n'"
  done

  print -- "'))\n${SCRIPT_TAGEND}"

  return 0
}
################################################################

email2hex "${@}"