Introduction
Many users run Linux from the command line. However, the command line, sometimes referred to as terminal, does not have an intuitive interface for checking disk space in Linux.
This guide shows how to find the size of a specific directory in Linux from the command line.
Prerequisites
A
- system running Linux
- command-line/terminal window (available by clicking Search and then typing terminal)A
- user account with sudo or root privileges
A
Option 1: Display the size of a directory by using the
du command
The du command means disk usage. This command is included by default in most Linux distributions.
You can display the size of your
current directory by typing du at the command line: du
The system should display a list of the contents of your home directory, with a number on the left. That number is the size of the object in kilobytes.
You can add the -h option to make the output more readable: du -h
Each entry will start with a number and a letter. The number is the amount of space used, and the letter (usually K, M, or G) indicates kilobytes, megabytes, or gigabytes. For example:
400K – 400 kilobytes 7.3M – 7.3 megabytes 2.2G – 2.2 gigabytes
To find the size of a specific directory different from your current working directory. The du command allows you to specify a directory to browse: du
-h /var
This displays the size of the contents of the /var directory. You may see some entries with an error, as in the image below.
This happens when your user account does not have permission to access a particular directory. Use the sudo or su command to get access privileges: sudo du -h /var To display the total disk usage of a particular directory, use the -c: sudo du -c /var
The
options can be combined. If you want to repeat the above command in human-readable format, type the following:
sudo du -hc /var
You can limit the scan to a certain subdirectory level using the max-depth option. For example, to scan only the size of
the top directory, use -max-depth=0: sudo du -hc -max-depth=0 /var If you want to
list only the top directory and the first layer of subdirectories, change -max-depth=1: sudo du -hc –max-depth=1
/var
If you have problems or want to explore more options for the du command, Enter the following command to display the help file
: man du
Option 2: Get the directory size
in Linux using the tree command
By default, the tree command is not included in some versions of Linux. To install it, enter the following:
For
- Debian/Ubuntu
sudo apt-get install tree
- For CentOS/RedHat
sudo yum install tree
The tree command displays a visual representation of the directories. It uses lines to indicate which subdirectories belong where, and it uses colors to indicate directories and files.
Tree can also be used with options. To display a human-readable size of the subdirectories in the current
directory, type the following: -d -h tree Like the du command, tree can point to a specific directory: /var tree This command
takes a few minutes because the /var directory has many entries.
The
tree command
also has a help file, which you can access by entering
: man tree
Option 3: Find the size of a Linux directory using the
ncdu command
The ncdu tool stands for NCurses Disk Usage. Like the tree command, it is not installed by default on some versions of Linux. To install it, enter the following:
For
- Debian/Ubuntu
sudo apt-get install ncdu
- For CentOS/RedHat
sudo yum install ncdu
The ncdu utility is an interactive disk usage screen. For example, type the following:
ncdu
In the upper-left corner, it displays the current directory being scanned. A column on the left shows the numerical size, a graph of #- signs to indicate the relative size, and the file or directory.
Use the up and down arrows to select different lines. The right arrow will navigate into a directory, and the left arrow will take you back.
ncdu can be used to point to a specific directory, for example:
ncdu /var
For help, press the ? key inside the ncdu interface. To exit, press the letter q.
Conclusion
You now have three different options for finding the size of a directory on Linux operating systems
.
If you want to learn more about directories in Linux, read our article how to rename directories in Linux.
