Renaming all files in a folder

Guys, i need to replace a particular pattern in lots of files in a folder with another pattern . Is there any command line script I can use to do the functionality.

Eg:

aalex > ls
green_1234_colour.max
red_1234_pen.max
yellow1234flower.max

Need to replace the 1234 in the file name with 9876 i.e,

aalex > ls
green_9876_colour.max
red_9876_pen.max
yellow9876flower.max

How can i do this??

Alex

$ for i in *1234*.max; do
mv -v "$i" "$(echo $i | sed 's/1234/9876/')"
done
green_1234_colour.max -> green_9876_colour.max
red_1234_pen.max -> red_9876_pen.max
yellow1234flower.max -> yellow9876flower.max
$ 

Thank u guys for the replay.
I think rename doesn't work for this situation as we need to look for a particular expression and replace it with a new pattern.

Why not ? rename is for renaming right ?! what expression you are thinking of ?

 
# ls
green_1234_colour.max  red_1234_pen.max  yellow1234flower.max
# rename 1234 9846 *
# ls
green_9846_colour.max  red_9846_pen.max  yellow9846flower.max

Sorry dude, i didint think like this..as this pattern comes in between...great.:b:.thanks