sed – noninteractive stream editor
The stream editor (sed) is a very popular noninteractive stream editor. Normally, whenever we edit files using the vi editor, we need to open the file using the
vi command, then we interact with the file, such as to see the content of the file on screen, then, edit it, and save the file. Using sed, we can type commands on the command line and sed will make the changes to the text file. The sed is a nondestructive editor. The sed makes the changes to the file and displays the content on screen. If we want to save the changed file, then we need to redirect the output of the sed to the file.
The procedure to install sed is shown here.
For Ubuntu or any Debian-based distributions enter the following command:
$ apt-get ...