How to create a file with a given size in Linux?

Question

For testing purposes I have to generate a file of a certain size (to test an upload limit).

What is a command to create a file of a certain size on Linux?

Answer 1

On OSX (and Solaris, apparently), the mkfile command is available as well:

mkfile 10g big_file

This makes a 10 GB file named "big_file". Found this approach here.