#!/bin/bash
#
# Author: Damian Myerscough
# Date: 27/02/2008
# Purpose: This little script will select at random a favourite icon 
#          from a directory containing more than one icon
#
# Note: For random images that only appear once create a pre_icon.txt 
#       file
#

# Web root
WWW_ROOT="/srv/www/htdocs"

# Directory with all your favourite icons 
FAVICON_DIR="/srv/www/favicon"

# A text file containing the previous icon (This file is optional)
FAVICON_CONFIG="/srv/www/prv_icon.txt"

NUM_OF_ICONS=$( ls $FAVICON_DIR | wc -l );
RANDOM_ICON=$( ls $FAVICON_DIR | head -n $[ $RANDOM % $NUM_OF_ICONS + 1 ] | tail -n 1 );

# Check to see if the prv_icon text file exists
if [ -e $FAVICON_CONFIG ]; then
    # Get the previous icon
    PREVIOUS_ICON=$( cat $FAVICON_CONFIG );

    # Make sure we are not dealing with an empty string
    if [ ! -z $PREVIOUS_ICON ]; then
       
        # Randomly pick an icon, if the icon was previously used pick a new one
        while [ $RANDOM_ICON = $PREVIOUS_ICON -a -e "$FAVICON_DIR/$PREVIOUS_ICON" ]; do
            RANDOM_ICON=$( ls $FAVICON_DIR | head -n $[ $RANDOM % $NUM_OF_ICONS + 1 ] | tail -n 1 );
        done; 
    fi;

    # Write the new icon to the previous icon file
    echo $RANDOM_ICON > $FAVICON_CONFIG

    # Copy the new icon
    cp "$FAVICON_DIR/$RANDOM_ICON" "$WWW_ROOT/favicon.ico"

else
    # Just randomly select an icon even if we have already had that icon
    cp "$FAVICON_DIR/$RANDOM_ICON" "$WWW_ROOT/favicon.ico"
fi;