Linux Shell Scripting Cookbook - Third Edition

Generating files of any size

A file of random data is useful for testing. You can use such files to test application efficiency, to confirm that an application is truly input-neutral, to confirm there's no size limitations in your application, to create loopback filesystems (loopback files are files that can contain a filesystem itself and these files can be mounted similarly to a physical device using the mount command), and more. Linux provides general utilities to construct such files.