Here’s what’s happening in the command;

for f in *; do

You already know this for loop, which is using the * glob to iterate over each directory in the current directory.

find ./"$f" -type f

Instead of your original ls command, which gives the file names, and not their full paths, we’re using GNU find, which outputs the full path of what it finds. The arguments are:

./"$f" - This tells find where to start its search. I double qouted the $f variable to properly expand the directory name even if it has nonstandard characters in it like spaces.

-type f - This tells find what kind of file object to look for. So it’s two parts. -type to tell find there will be a specific type to look for, and the f flag, which means file. Meaning, it will only find files

The output of find is not sorted alaphabetically, so before piping the output to tail, we first pipe it to sort, which by default will sort alphanumerically, which we then pipe to tail to grab just the last two files, and finally we get to the xargs bit.

Here I added the -n 1 argument to xargs to get it to work on the files one at a time. This isn’t actually necessary. You could just run it as xargs rm. I didn’t realize that before I posted the command. (I’m still learning too! The learning never ends. :D )