Get more out of the ls command

The ls command is a well-known and often used command-line program that is used to list directory contents by name; in fact, it could be argued that it is the most used Linux command-line program.

$ ls

MD5SUMS annvix-netinstall-i586-2.0-RELEASE.iso bin mc-vdanen

In addition to its most basic use, the ls command has a number of options that will provide additional information. To get a long listing of every file in a directory, including the hidden files, use:

$ ls -la

total 363604

drwx------ 3 vdanen vdanen 91 Jun 2 16:02 .

drwx -- x--x 18 vdanen vdanen 4096 Jun 2 15:07 ..

-rw-r -- r-- 1 vdanen vdanen 73 Feb 4 21:53 MD5SUMS

-rw-r -- r-- 1 vdanen vdanen 372318208 Feb 4 20:19 annvix-netinstall-i586-2.0-RELEASE.iso

lrwxrwxrwx 1 vdanen vdanen 6 Jun 2 16:02 bin -> ../bin

drwx------ 2 vdanen vdanen 6 Mar 2 2004 mc-vdanen

...

To display the long listing in a human readable format that nicely summarises the file sizes, use:

$ ls -lah

total 356M

drwx------ 3 vdanen vdanen 91 Jun 2 16:02 .

drwx -- x--x 18 vdanen vdanen 4.0K Jun 2 15:07 ..

-rw-r -- r-- 1 vdanen vdanen 73 Feb 4 21:53 MD5SUMS

-rw-r -- r-- 1 vdanen vdanen 356M Feb 4 20:19 annvix-netinstall-i586-2.0-RELEASE.iso

lrwxrwxrwx 1 vdanen vdanen 6 Jun 2 16:02 bin -> ../bin

drwx------ 2 vdanen vdanen 6 Mar 2 2004 mc-vdanen

To include visual identifiers of different file types, use the -F option. This will show directories by suffixing their name with a backslash (/) character, symbolic links by suffixing the file name with @, and so on:

$ ls -F

MD5SUMS annvix-netinstall-i586-2.0-RELEASE.iso bin@ mc-vdanen/

There are other options for ls worth exploring. To do a long list without the permissions and size information, use the -1 option. To view the listings in color, use --color=auto. To list the files in reverse, use -r. To show a colored long list, in reverse, of just filenames, use ls -1 -r --color=auto. As you can see, you can use many options in conjunction with one another.

If you find a listing format that you like, create an alias for it so when you invoke ls on the command-line, you'll always use your preferred format, such as by adding the following to ~/.bashrc:

alias ls="/bin/ls -Fh --color=auto"

Use ls --help or man ls to get more information on the many different options you can use with ls to customise its output.