I tend to download pictures from Pinterest from various projects.
Since most of them were uploaded without a title, every file is named `_.jpeg`.
This is annoying.
I wanted a clean way to rename all files in a folder on macOS.
Here's the bash code you can copy-pasta into your terminal.
```bash
for f in *; do
ext="${f##*.}"
mv -- "$f" "$(uuidgen).$ext"
done
```
This preserves file extensions.