If you read my previous Ubuntu permission post, then you should have noticed one of the ls command options that I used, which is the ls -l option. Actually the -l is an option to view long listing format. That way we can see the details of the file, such as the permission and file ownership. Below are examples of other useful ls command options normally used in Ubuntu.
Example 1 - Ubuntu standalone ls command, no option.
ls command is one of Ubuntu commands that can be used without an option. As you can see in the picture above, the ls command without option will list the directory contents. A directory, file and link is identified with different colors.
Example 2 - Ubuntu ls command with -a option.
luzar@ubuntu:/$ ls -a
. boot etc initrd.img media proc sbin tmp vmlinuz
.. cdrom home lib mnt .rnd srv usr
bin dev initrd lost+found opt root sys var
luzar@ubuntu:/$
The -a option lists all contents in directory including hidden files. A few years ago, people hide their nasty file using . and whitespace. But today, that trick won't work anymore.
Example 3 - Ubuntu ls command with -F option.
luzar@ubuntu:~$ ls -F
file.txt* folder/
luzar@ubuntu:~$
The -F option prints file types.
Example 4 - Ubuntu ls command with -g option.
luzar@ubuntu:~$ ls -g
total 4
-rwxrwxrwx 1 luzar 0 2011-05-21 03:43 file.txt
drwx------ 3 luzar 4096 2011-05-21 11:14 folder
luzar@ubuntu:~$
The -g option prints long listing like -l but without owner. To prints owner without group, use -o.
Example 5 - Ubuntu ls command with -h option.
luzar@ubuntu:~$ ls -h
file.txt folder
luzar@ubuntu:~$ ls -hl
total 4.0K
-rwxrwxrwx 1 luzar luzar 0 2011-05-21 03:43 file.txt
drwx------ 3 luzar luzar 4.0K 2011-05-21 11:14 folder
luzar@ubuntu:~$
The -h option itself means nothing. But combine with -l, it prints size in human readable format.
Example 6 - Ubuntu ls command with -i option.
luzar@ubuntu:~$ ls -i
8201 file.txt 8200 folder
luzar@ubuntu:~$
The -i option prints the index number of each file.
Example 7 - Ubuntu ls command with -m option.
luzar@ubuntu:~$ ls -m /var
backups, cache, lib, local, lock, log, mail, opt, run, spool, tmp, www
luzar@ubuntu:~$
The -m option prints a comma separated list of entries.
Example 8 - Ubuntu ls command with -r option.
luzar@ubuntu:~$ ls -r /var
www tmp spool run opt mail log lock local lib cache backups
luzar@ubuntu:~$ ls -rl /var
total 40
drwxr-xr-x 2 root root 4096 2011-05-19 15:17 www
drwxrwxrwt 2 root root 4096 2011-05-13 10:14 tmp
drwxr-xr-x 4 root root 4096 2011-05-19 15:17 spool
drwxr-xr-x 11 root root 400 2011-05-21 09:22 run
drwxr-xr-x 2 root root 4096 2011-05-19 15:10 opt
drwxrwsr-x 2 root mail 4096 2011-05-20 13:53 mail
drwxr-xr-x 10 root root 4096 2011-05-21 09:22 log
drwxrwxrwt 3 root root 60 2011-05-21 09:22 lock
drwxrwsr-x 2 root staff 4096 2011-05-13 10:14 local
drwxr-xr-x 27 root root 4096 2011-05-19 15:19 lib
drwxr-xr-x 9 root root 4096 2011-05-19 15:17 cache
drwxr-xr-x 2 root root 4096 2011-05-19 15:10 backups
luzar@ubuntu:~$
The -r option prints directory content reversely.
Example 9 - Ubuntu ls command with -R option.
luzar@ubuntu:~$ ls -R
.:
file.txt folder
./folder:
new_file.txt new_folder
./folder/new_folder:
luzar@ubuntu:~$
The -R option lists subdirectory recursively. As from the example, we can also see the content in the folder directory.
Example 10 - Ubuntu ls command with -s option.
luzar@ubuntu:~$ ls -s
total 4
0 file.txt 4 folder
luzar@ubuntu:~$
The -s option sorts content by file size.
That's ten examples of useful Ubuntu ls command option guides that you can use to manage your system. Another useful options are:
-t = to sort content by modification time.
-X = to sort alphabetically by extention.
-v = to sort by version.
