While working from Vim itself, you can execute external commands. To execute and view the output of a command, at the command line, use :!command, where 'command' is the command you want to execute. For example, to execute Is, try.

It is also possible to paste the output of the executed command to the currently working file by using:r !command.

Vim has awesome features to process the contents of the file using external commands and to paste the output back to the file. It is also able to process text between a range of lines.

There are situations when a part of the text needs to be processed. Vim makes it convenient to process a given range of lines using external commands.