Create a test file of a certain size

There are a number of possible reasons you may want to create a file of a specific size. For example:

• Testing upload/download speed (you may want a very large file, for example)
• Testing edge conditions related to file size
• Test the behavior of a mix of large and small files

Probably one of the least complicated UNIX utilities every written is called mkfile and is designed for this purpose. It’s super simple to use:

mkfile <size> <filename>

For size, you just use a number, suffixed by b(bytes), k(kilobytes), m(megabytes), g(gigabytes). So, a specific example:

mkfile 10g TenGigabyte.txt

This creates a 10 gigabyte file called TenGigabyte.txt.

The files will all just be zeroes, but for many purposes, this is fine.