You can easily list the files and directories in Linux. You may already know the ‘ls’ command. ‘ls’ refers to list. It list all the files and directories available. There are various ways you can use the ‘ls’ command. Here are the guide to use ls command in Linux and UNIX with different examples.
| -a | Shows you all files, even files that are hidden (these files begin with a dot.) |
| -A | List all files including the hidden files. However, does not display the working directory (.) or the parent directory (..). |
| -b | Force printing of non-printable characters to be in octal ddd notation. |
| -c | Use time of last modification of the i-node (file created, mode changed, and so forth) for sorting (-t) or printing (-l or -n). |
| -C | Multi-column output with entries sorted down the columns. Generally this is the default option. |
| -d | If an argument is a directory it only lists its name not its contents. |
| -f | Force each argument to be interpreted as a directory and list the name found in each slot. This option turns off -l, -t, -s, and -r, and turns on -a; the order is the order in which entries appear in the directory. |
| -F | Mark directories with a trailing slash (/), doors with a trailing greater-than sign (>), executable files with a trailing asterisk (*), FIFOs with a trailing vertical bar (|), symbolic links with a trailing at-sign (@), and AF_Unix address family sockets with a trailing equals sign (=). |
| -g | Same as -l except the owner is not printed. |
| -i | For each file, print the i-node number in the first column of the report. |
| -l | Shows you huge amounts of information (permissions, owners, size, and when last modified.) |
| -L | If an argument is a symbolic link, list the file or directory the link references rather than the link itself. |
| -m | Stream output format; files are listed across the page, separated by commas. |
| -n | The same as -l, except that the owner’s UID and group’s GID numbers are printed, rather than the associated character strings. |
| -o | The same as -l, except that the group is not printed. |
| -p | Displays a slash ( / ) in front of all directories. |
| -q | Force printing of non-printable characters in file names as the character question mark (?). |
| -r | Reverses the order of how the files are displayed. |
| -R | Includes the contents of subdirectories. |
| -s | Give size in blocks, including indirect blocks, for each entry. |
| -t | Shows you the files in modification time. |
| -u | Use time of last access instead of last modification for sorting (with the -t option) or printing (with the -l option). |
| -x | Displays files in columns. |
| -1 | Print one entry per line of output. |
| pathnames | File or directory to list. |
1) ls -l:
List the file with long format. The command will list be listed into different formation which include file permission, size of the file, date of the last modification and the file name or directory respectively.
Permissions - The permissions of the file or directory.
Directories - The amount of links or directories within the directory. The default amount of directories is going to always be two because of the . and .. directories.
Group - The group assigned to the file or directory
Size - Size of the file or directory.
Date - Date of last modification.
Directory of file - The name of the file or file.
2) ls -a:
If you add ‘-a’ with the ls command. It will show the hidden files and folders. If you don’t know how to hide and unhide files in Linux, take a look at how to hide and unhide files in Linux. Normally, the hidden file have ‘.’ at it’s beginning. 
3) Listing some important directory
ls ~ : List the contents of your home directory by adding a tilde after the ls command.
ls / : List the contents of your root directory.
ls ../ : List the contents of the parent directory.
ls */: List the contents of all sub directories.
ls -d */ :Only list the directories in the current directory.
4) Wild cards:
If you want to search the file that start with “assign”, you would type ls assign*. It will list the file that start with assign.
If you want to search the file that ends with .odt, you would type *.odt.
So, it’s a good idea to add some fancy extension while naming the file so that it would be easy for you to search. For example: You can create file name my_girlfriend.letter which you can search letter on just by type *.letter.
5) List the file begin with some range[For example: a-d]
If you want to search the file that begins with the letter a, b, c and d type ls [a-d]*.
on 
on 
on 
[...] I am going to rename the command “ls -l” to lsl . “ls -l” lists the file with long formation which includes permissions, date etc. If you are unknown about ls command, check the usage and power of ls commands. [...]