A reader who wishes to remain anonymous would prefer to forego some busy work. He writes:
I’ve been working on a project for a couple of months where I created a few hundred files using this naming format:1.1 My File Name.txt
. I’ve just been told that I have to use a different format:1_1_my_file_name.txt
because of how the files are tracked in the company’s database. I don’t want to do this by hand. Do you have any tips for speeding up the process?
If you’re willing to cough up $20, Publicspace.net offers a great solution in the form of A Better Finder Rename. If you need to do this kind of thing routinely, it’s worth the money.
But you can also do this for free with Automator. Like so:
Launch Automator and from the template chooser select Application. In the resulting window enter rename
in the Search field. Drag the first result—Rename Finder Items—into the workflow area to the right. You’ll be offered the opportunity to make copies of any files the workflow affects. It’s up to you whether this seems like a good idea or not. Drag two more instances of this action into the workflow area but decline the offer to create additional copies of your files.
In the first two actions choose Replace Text from the first pop-up menu. In the first action’s Find field enter a period (.) and choose Basename Only from the next pop-up menu. In that action’s Replace field enter an underscore ( _ ).
In the next Rename Finder Items action type a space in the Find field, also choose Basename Only in the pop-up menu, and again enter an underscore character in the Replace field.
In the third action choose Change Case from the first pop-up menu and change the other two to read Basename Only Is Lowercase
.

Rename your files with a workflow similar to this.
Save the workflow as an application and place it on your Mac’s desktop.
Now select one of the files you wish to rename and drop it on top of the application. If it provides you with the results you wish, select all of the rest of the files and drop them on the application as well. Automator will churn through the workflow and rename the files.