bulk renaming with dc

The Double Commander file manager has a tool for quickly bulk renaming a list of files. I tested it out in Kubuntu 17.10, using Double Commander version 0.8.0 beta. The files I wanted to rename were located in my directory named ~/testdirectory, shown here in Double Commander's left panel:

First, I selected the files by clicking Mark > Select All from the toolbar:

That done, I clicked Files > Multi Rename Tool; alternatively, the Ctrl+M keystroke works:

The Multi Rename Tool window looked like this at first:

Here's how I set things up:

Then I clicked the "Rename" button. Result:

Double Commander's Multi Rename Tool is a powerful tool with many options. Users might want to play around with it a bit to get things figured out; for more info, see the "Multi Rename Tool" section in Double Commander's Help document, under 3.1.1 "Files".