The ls program prints human-readable listings of directories. By default, with no arguments, this list is just the names of each file in the current directory, printed horizontally for readability:
$ ls books documents music
If we add the -a flag, we can include dot files in our output, files beginning with a period:
$ ls -a . .. .bashrc .profile books documents music
Note that this output includes the . and .. entries, referring to the current and parent directory, respectively.
Using the -l option, which can be combined with -a, we can get a long listing of files:
$ ls -al drwxr-xr-x 91 bashuser bashuser 16384 Jul 7 19:50 . drwxr-xr-x 5 root root 4096 Jun 1 20:28 .. -rw-r--r-- 1 bashuser bashuser 3391 Jun 30 01:03 .bashrc ...
