Quickly create a large file on a Mac OS X system?

Question

In order to create a 10 GB temp file...

In Linux you can do this:

fallocate -l 10G temp_10GB_file 

In Windows you can do this:

fsutil file createnew temp_10GB_file 10000000000 

...but what about if you're in OS X?

Answer 1

macOS has the command mkfile to achieve the same:

mkfile -n 10g temp_10GB_file 

Syntax:

mkfile [ -nv ] size[b|k|m|g] filename ... 

And here's the related manual page for mkfile

Cross Platform Alternative (Unix including macOS):

As an alternative you could also you the Unix util dd:

dd if=/dev/zero of=temp_10GB_file bs=1 count=0 seek=10G 

Note that on macOS you need to use a lowercase for the unit as follow:

dd if=/dev/zero of=temp_10GB_file bs=1 count=0 seek=10g 

And here's the related manual page for dd