#!/bin/sh

set -e

PROG="$0"

ciscowipe() {
    # Remove secure-web.cisco.com prefix
      sed -E "s!https?://secure-web.cisco.com/[^/ ]*/!!g" |
    # URL decode
     # Decodes all URL escape sequences
     #sed -e 's!+! !g;s!%\([0-9A-Fa-f]\{2\}\)!\\x\1!g' | xargs -0 printf "%b"
     # Decodes only some escape sequences, but leaves others, like spacs,
     # as is.
     sed 's!%3A!:!g;s!%2F!/!g;s!%3F!?!g;s!%3D!=!g;s!%26!\&!g'
}

usage() {
    cat<<EOF
Mr. Clean for Cisco's mail snakeoil. It restores the original URL from the URL
generated by Cisco's mail security software.

Usage:
    $PROG -h
    $PROG [FILE]...

If no filename is given then stdin is processed. Otherwise all files passed are
processed.
EOF
}

if [ "$#" -eq 0 ]; then
    ciscowipe
else
    for f in "$@"; do
        if [ "$f" = "-h" ]; then
            usage
            exit
        fi
        cat "$f" | ciscowipe
    done
fi