UNIX Command
$ls a1.txt a2.txt $ls . ./ ../ $cp a1.txt a1.txt~ $ls a1.txt a1.txt~ a2.txt $ls -B a1.txt a2.txt $l bash: l: command not found $ls a1.txt a1.txt~ a2.txt $ls --backup ls: unrecognized option '--backup' Try `ls --help' for more information. $ls --ignore-backups a1.txt a2.txt $