@sjmulder For similar example, some years ago, a friend wanted to copy a large number of images, and get rid of spaces in file names. I plugged his disk into a System 76 Ratel (several years old), ran ls, used emacs to create a script with a series of 'cp' commands, and started the script. After a minute or two of us chatting, I looked at the screen and the program had finished. He was blown away - it would have taken over an hour on his Apple system: showing progress is expensive.