General :: Scripting To Move Thousands Of Files Into Folders

Our client has a website (Joomla 1.5 based) to promote participation in and report results of a 10k race for runners in Scandinavia...

The race is scheduled for late June and will be covered by at least 5 still photographers at various points along the race course.

There are to be about 5,000 runners, each entered under a shirt number like bib_1000 through bib_5999, and this means there will be a significant number of digital jpg files submitted by the photographers...

The client has in place some software which will "automagically" resize, watermark, and rename the individual files in the form:

And so on with a possibility of as many as 10 or 12 images in the aggregate with the same alpha-numeric "shirt number" at the beginning of the filename.

Our presentation software does a great job of handling thumbnail image generation and displaying a slideshow in a lightbox of all files within a given folder on the webserver.

And now finally the question...

Given a folder containing 25,000 or so *.jpg files, how can we write a script that:

1. parses the filenames to unique "shirt numbers"
2. makes folders with each "shirt number" as the foldername
3. moves the files from the root of the original folder into the appropriate "shirt number" folder.

Note that the order of my list above is not important, and if you know of a better way to organize the task we are fine with that.