To install GNU Cut in OSX

The commands are provided with a g prefix:

Mithos:~ verence$ ls -l /usr/local/Cellar/findutils/4.4.2/bin
total 1328
-r-xr-xr-x  1 verence  admin  233400 Nov 13 05:03 gfind
-r-xr-xr-x  1 verence  admin  143620 Nov 13 05:03 glocate
-r-xr-xr-x  1 verence  admin  229704 Nov 13 05:03 goldfind
-r-xr-xr-x  1 verence  admin    9837 Apr  3 15:09 gupdatedb
-r-xr-xr-x  1 verence  admin   49796 Nov 13 05:03 gxargs
Mithos:~ verence$ type gfind
gfind is /usr/local/bin/gfind

If this is the first time you are using brew to install software, make sure to include /usr/local/bin in your PATH. There is no need to add other paths for brew.

If you want to get the size of a mounted block device (which is what blockdev -getsize64 does), you can use the following:

diskutil information <device> | grep "Total Size" | sed -e 's/[^(]*(([^Bytes)]*\).*/\1/'

If you want to do the same for a file, you can use the following (amongst many others):

stat -f '%z' <filename>