ls
Firstly, your ls
is probably aliased to something.
Check it with:
alias ls
If the prompt shows some alias, then start by removing it:
unalias ls
Now we can begin.
Check the most recently modified file:
ls -t
Reverse this with tac
to see the file which has been unmodified the longest:
ls -t | tac
Group files by extension:
ls -X
Sort largest files first:
ls -X