In this article, we are going to discuss the dd command. The dd command stands for data duplicator. It is mainly used for converting and copying files. In this section, we are going to learn about backing up and erasing a media file.

Prerequisites

Besides having a terminal open, we need to make sure you have the necessary files present in the current directory to take backups, to make copies, and similar tasks.

How to do it

The dd command is mainly used for converting and copying files. The if parameter stands for input-file and is a source. of stands for output-file and is a source where we want to paste data.

Run the following command to copy the contents of one file to another:

# create a file 01.txt and add some content in that file. 
# create another file 02.txt and add some content in that file. 
$ dd if=/home/student/work/01.txt of=/home/student/work/02.txt bs=512 count=1

Run the following command to take a backup of the partition or the hard disk:

$ sudo dd if=/dev/sda2 of=/home/student/hdbackup.img

The dd command is also used to erase all of the contents of the disk. Run the following command to delete the contents:

$ sudo dd if=/home/student/work/1.sh

How it works

Now we will see how the preceding commands work:

• We used the dd command to copy the contents of the 01.txt file into the 02.txt file.
• To run this command, we must have super user privileges. Using the dd command, we took a backup and stored it in the hdbackup.img file.
• Using the dd command, we erased the contents of the 1.sh file.