Helpful for when you want to change the name of a sequence of images at the same time.

rename-files.sh

# /bin/bash

# 
# Helpful for when you want to change the name of a sequence of images at the same time.
# 
# Author: Rafael Rinaldi (rafaelrinaldi.com)
# Since: 15/04/2011
# 

path=$1
base_name=$2
count=0

if [[ ! -d $path ]]; then
	echo "Invalid path!";
	exit;
fi

for file in $path/*.*
	do  
		# Keep the same extension of the original one.
		extension=`echo $file | awk -F . '{print $NF}'`;
		
		mv "$file" "$path/$base_name$count.$extension";
		
		(( count++ ));
	done

in ruby

#!/usr/bin/env ruby

path = ARGV[0]
base_name = ARGV[1]

Dir["#{path}/*.*"].each_with_index do |file, index| 
   new_file = "#{File.dirname(file)}/#{base_name}#{index}#{File.extname(file)}"
   `mv #{file} #{new_file}`
end

Cool! Thanks for sharing :)