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 summarizes 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 customize its output.
>>Related tip: Customizing colors with the ls utility
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