Creating empty copies of files with new extensions

Question

I have AIX 7.1. Let's say I have a directory with files like these:

1.txt
lala.csv

I need to create empty copies of these files with a new extension in the same directory, like so:

1.txt.done
lala.csv.done

I can't seem to find the right option for doing this.

Answer 1

Simply loop over every file (here, skipping dotfiles by default), and touch the corresponding file:

for f in *; do touch "${f}.done"; done

• xaren jo: could you also clarify what does $ do in this command?
• Jeff Schaller: Sure, @xarenjo ; it introduces a variable expansion. I used curly braces out of habit, to explicitly delineate what the variable is (f). The end result is that the touch command sees the value of $f — each existing filename — during each loop.
• ctac_: Or with redirection : for f in *; do > "${f}.done"; done